Creating an array in a 'for' loop (resetting loop count)

Hi,
I am trying to integrate an acceleration signal coming from a CRIO analogue input to obtain the speed and then further integrate to get the displacement of a vibration system.
I understand that in order to perform the integration, an array has to be fed in. My problem is that I could not buffer the signal in a buffer block as I couldn't find any buffer blocks. so I decided to create my an array of data using a 'for' loop. The 'for' loop nests inside a timed loop. The problem that I got stuck at is how to reset the 'for' loop in order to refill the buffer again at every iteration of the outer timed loop.
I have attached the code if that helps. Note that I am using labview 2013.
I would be gratefull if someone who had encountered a similar issue before can help me.
Regards
Ali
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Attachments:
acc_test.vi ‏42 KB

Dear Altenbach,
Many thanks for your reply.
I need to make it clear that I have not had enough hands-on with labview, I have only used it for sometime in the past and now I have to in order to perform some active damping on a 50Hz running machine. I must stress the fact that what i find more intuitive to do in a different programming language (matlab or C) is not as straightforward in labview. so please bear with me if my code has basic mistakes .
All what i am trying to do is obtain the speed and position from an acclerometer signal. unfortunately i dont have a position sensor so i have to measure acceleration then perform time integrations in order to obtain the speed and position respectively. I am using a compact Rio (later in FPGA mode) to take physical measurements of acceleration from the vibratory machine and where i managed to do this bit successfully. when it came to performing the integration, i had to create an array inside my timed loop since i couldn't find a buffer block. I implemented a 'for' loop inside a timed loop in order to build the array. however i got stuck at resetting the count of the 'for' loop in order to refill the array with new values at every new iteration of the outer timed loop. unfortunately, even a sensible answer has been suggested before, i dont seem to have been capable of doing it yet. I really spent all my day trying to figure a way out but not achieved it yet, nevertheless I have learnt many many things by playing around.
I would be gratefull if you could comment on a possible way of doing what i am trying to do.
Kind Regards
Ali

Similar Messages

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I tried to create the local variable that was wired to numeric indicator inside the loop. If I try to connect this to the analog output outside the loop, the loop just starts blinking and nothing happens, am I doing something wrong? Thanks again.
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Resetting a for loop counter and restarting the computation

I have a while loop nested inside a for loop to do a calculation of a model.
Lets say I am on the for loop counter 4. Suppose I wanted to keep track of the number of iterations on one the while loop, and if it exceeded a certain number say 100, exit the while loop. I am doing this to avoid my model calculation being stuck at a spot due to optimization issues. I now want to restart the calculations of for loop counter 4.
Is there a way to do this in labview?
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Well first of all, if you are going to restart the loop with the same program inside it after it got stuck is it not just going to get stuck again creating a permanent loop in the code? Would you not just want to move on and have some sort of identifier that one of the for-loops got stuck?
But I would recommend simply nesting your while-loop inside of another while loop, then connect the exit for the out while-loop to some variable from the inner while-loop, so if the optimization did not occur properly then it simply repeats the inner while-loop.
Although I stick by my thoughts that you will just end up in a permanent loop if the optimization fails the first time.

Transposing data in an array using a For Loop

I am trying to transpose some data in an array using a for loop starting from the size of the array then decrement down to 0. Can someone please help if you have an example?
Solved!
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I feel as if reverse 1D array may help
Edit: misunderstood what your second post meant.
CLA, LabVIEW Versions 2010-2013

Truncating an array within a for loop

I'm currently working with a program that builds an array of 3000*N real numbers, where N is a control that I specify. I want to pass this array into a for loop that runs N times, each time splitting the first 3000 numbers of the array. So, in other words I want the for loop to execute enough times such that the initial array will be completely divided into groups of 3000 when I'm finished. Later I'll be finding the maximum value of all of these subarrays and taking the average of those. What I tried first is to pass the array into the for loop, then truncate it at index = 3000, but the problem is that I can't hard code the loop to do this N times. Any advice or other methods you'd recommend for doing this?
Thanks.
Message Edited by Robtn on 03-05-2010 03:17 PM

Mark--I don't think I can use that approach. Let me be more specific on what the problem is:
Our "big program" is a giant while loop that constantly reads in voltage values from a DAQ assistant.
It has two modes, the first of which I'm having a lot of trouble with. This mode uses a for loop (N = 3000) nested within the giant while loop.
When the for loop activates, the DAQ assistant takes reads 300 samples for every iteration and takes the maximum of those 300 values. It then builds an array composed of all the maxima. After the for loop has executed 3000 times, a case structure activates, which then finds the maximum of the array of maxima.
I want this (N=3000) for loop to execute an arbitrary number of times, a number that I will specify. Each of those times it should generate a completely seperate array of maxima. So, if I want the for loop to run 5 times, I want 5 different arrays.
My approach for doing this was to change N=3000 to say N = 15000, then split up the resulting array 5 times. So, I need an entirely separate for loop that reads in this array of 15000 maxima on its own and splits it 5 ways. I think what you're suggesting is to use a for loop outside of the N=3000 loop, which is a good idea in theory, but experience has shown that this will not generate 5 separate arrays. It will actually concatenate each array into one, hence the problem we currently have.
Yik--I won't have access to Labview over the weekend. Is it possible to take a screenshot and post it, or maybe a short description?
Thank you for the responses.

LabVIEW 6.1 If For Loop count terminal is zero then value going through the loop is not passed on to the output of the loop

Hello, one of our customers just encountered an execution error in a vi running under LabVIEW 6.1, which doesn't exist under LabVIEW 5.1 or 6.01. I have a simple vi that has two encapsulated For Loops. Two string arrays go in, one goes out of the outer loop. Inside the outer loop the first array is indexed. The string which results from this indexing is compared with all other strings from the second string array in the inner loop. If it matches one of the strings of the second array, it is not outputted, otherwise this string goes through the inner For Loop to the output of the inner loop and from there to the output of the outer loop. The count
terminal of the outer/inner loop is connected to the Array Size of the first/second string array. If the second array is empty, that means that the element in test from the first arry cannot match anything from the second array, so the element in test is send to the output of the inner loop and from there to the output of the outer loop. This works fine in LabVIEW 5.1 and 6.01, but NOT in LabVIEW 6.1. In LabVIEW 6.1 the inner loop is never executed if the count value is zero (which is correct), but the data line running through the loop is not executed either, which is different to what LabVIEW 5.1 and 6.01 do. There, the input string is sent to the output of the inner loop correctly even if the loop counter is zero. The solution is easy - I just have to connect the output of the outer loop to the data line BEFORE it enters the inner loop. But: I don't know if this is a LabVIEW 6.1 bug or if it is supposed to be a feature, but it brings some incompatibility in programming between the
different LabVIEW versions.
Best regards,
Gabsi

Hi,
When a for-loop runs zero times, all outputs are 'undefined' (and should
be).
Besides, how would LV know what the output of a not executed routine should
be?
It might be handled differently in LV5 and LV6, which is unfortunate. In
both cases, the result is undefined.
It's not a bug. It's just something that should be avoided in any LV
version.
> The solution is easy - I just have to connect the
> output of the outer loop to the data line BEFORE it enters the inner
> loop. But: I don't know if this is a LabVIEW 6.1 bug or if it is
In some cases this does the trick. But if the data is changed in the inner
loop, this will effect the results if the N is not zero.
Technically, I think the output in this construction is also 'undefined'.
But LV handles this as expected / desired.
Another solution is to use a shift register. If N is zero, the input is
directly passed through to the output.
Regards,
Wiebe.
"Gabs" wrote in message
news:[email protected]...
> LabVIEW 6.1 If For Loop count terminal is zero then value going
> through the loop is not passed on to the output of the loop
>
> Hello, one of our customers just encountered an execution error in a
> vi running under LabVIEW 6.1, which doesn't exist under LabVIEW 5.1 or
> 6.01. I have a simple vi that has two encapsulated For Loops. Two
> string arrays go in, one goes out of the outer loop. Inside the outer
> loop the first array is indexed. The string which results from this
> indexing is compared with all other strings from the second string
> array in the inner loop. If it matches one of the strings of the
> second array, it is not outputted, otherwise this string goes through
> the inner For Loop to the output of the inner loop and from there to
> the output of the outer loop. The count terminal of the outer/inner
> loop is connected to the Array Size of the first/second string array.
> If the second array is empty, that means that the element in test from
> the first arry cannot match anything from the second array, so the
> element in test is send to the output of the inner loop and from there
> to the output of the outer loop. This works fine in LabVIEW 5.1 and
> 6.01, but NOT in LabVIEW 6.1. In LabVIEW 6.1 the inner loop is never
> executed if the count value is zero (which is correct), but the data
> line running through the loop is not executed either, which is
> different to what LabVIEW 5.1 and 6.01 do. There, the input string is
> sent to the output of the inner loop correctly even if the loop
> counter is zero. The solution is easy - I just have to connect the
> output of the outer loop to the data line BEFORE it enters the inner
> loop. But: I don't know if this is a LabVIEW 6.1 bug or if it is
> supposed to be a feature, but it brings some incompatibility in
> programming between the different LabVIEW versions.
> Best regards,
> Gabsi

Passing an array in a for loop to a procedure

I am trying to pass an array in a cursor for loop to a procedure which performs a table insert using the array's contents. Somehow I am missing something, or it is not possible. The compile error states: PLS-00306: wrong number or types in call to 'insert_address' I checked to be sure I am creating the arrays in both cases from similar data objects. Both address and work_address_table contain the same 4 columns with the same data types.
create or replace package work_address as
FUNCTION populate_address return boolean;
procedure insert_address(in_address IN work_address_table%ROWTYPE);
end work_address;
create or replace package body work_address as
function populate_address return boolean is
cursor c1 is
select 'H' as header,
street1 as street
city as city,
NULL as state
from address
where city = 'HANOVER';
TYPE addressT IS TABLE OF c1%ROWTYPE INDEX BY BINARY_INTEGER;
rec1 addressT;
BEGIN
OPEN c1;
FETCH c1 BULK COLLECT INTO rec1 LIMIT 500;
FOR i IN 1..rec1.count LOOP
rec1(i).state := 'US'
insert_address(rec1(i));
exit when c1%notfound;
END LOOP;
CLOSE c1;
return TRUE;
END populate_address;
PROCEDURE insert_address(in_address IN work_address_table%ROWTYPE) IS
BEGIN
INSERT INTO work_address_table
VALUES (in_address.header,
in_address.street,
in_address.city,
in_address.state);
COMMIT;
END insert_address;
END work address;
/

Both address and work_address_table contain the same 4 columns with the same data types.Are you 100% sure about this?
SQL> declare
cursor c1
is
    select 1 deptno, dummy dname, 'Loc' location from dual;
type addresst is table of c1%rowtype
    index by binary_integer;
rec1   addresst;
procedure p (d dept%rowtype)
as
begin
    dbms_output.put_line(d.dname);
end p;
begin
rec1 (1).dname := 'z';
p (rec1 (1));
end;
z
PL/SQL procedure successfully completed.but changing just the first column of the cursor:
SQL> declare
cursor c1
is
    select 'xy' deptno, dummy dname, 'Loc' location from dual;
type addresst is table of c1%rowtype
    index by binary_integer;
rec1   addresst;
procedure p (d dept%rowtype)
as
begin
    dbms_output.put_line(d.dname);
end p;
begin
rec1 (1).dname := 'z';
p (rec1 (1));
end;
Error at line 3
ORA-06550: line 20, column 3:
PLS-00306: wrong number or types of arguments in call to 'P'
ORA-06550: line 20, column 3:
PL/SQL: Statement ignored

Create multiple VIs using a for loop

Hi,
I'm still pretty new to LabVIEW, so this question might be easy for you guys here..
I'll simplify what I'm trying to do.
I've got two numeric controllers that act as the rows and columns of a matrix.
I'd like to take those numbers from these two controllers and use them to create a matrix of a certain picture.
Example:
The rows controller is given 3, and the columns controller is given 4.
Using these numbers I would like the end result to show a certain image (let's say, a cube) multiplied on a 3 by 4 matrix.
Let's say the picture is an X, then the end result should be:
XXXX
XXXX
XXXX
I think I should be using a double for loop (one inside the other obviously), and I should also create the "position" property in order to display each picture of the cube in it's right place.
The problem is that I don't know how to CREATE the pictures over and over again, while being able to control each one's position property.
Any help would be GREATLY appreciated!
Solved!
Go to Solution.

1) By "multiple VIs" I meant that I think that I need to create express VIs on the fly while running the for loop. I might be totally wrong here.
2) Yes, by "numeric controllers" I meant numeric controls in the front panel.
3) The matrix I'm referring too isn't an object nor a VI in LabVIEW but a virtual matrix that is the end result. I used the term "matrix" because the end result is actually a matrix (of rows and columns) of pictures..
I'll try to elaborate and even simplify it more:
Let's say I want to display one picture. That's easy, no problem there.
Now let's say that I'd like to display n pictures on a one dimensional array. Just one row.
What I think I need to do is to read from the numeric control in the front panel the number (n) of pictures, and then create them in a for loop, while using the "position" property to set the distance between each picture (using coordinates).
My original question was just like the above, but for a two dimensional matrix/array. So I guess we can even simplify it even more, by saying it's only one dimensional.
My way of action here might be totally wrong, and there might be an easier way or another way to go about this...
Thanks for the quick answer!!

How to output last 4 arrays from a For Loop?

Hi People,
I am almost at the end of my tether. I really hope someone could please help me.
Any input would be welcome. VI attached.
VI explanation:
I initialize an array.
The random number generator simulates my camera input.
Depending on which iteration it is, the data is added into one of four output arrays.
'x-y*floor(x/y)' gives a remainder value of 0, 1, 2 or 3.
'Case Selector' just adds 1 to 'x-y*floor(x/y)' to get case 1, 2, 3 or 4.
Shots 1, 5, 9 etc are added to Array 1 (Case 1).
Shots 2, 6, 10 etc are added to Array 2 (Case 2).
Shots 3, 7, 11 etc are added to Array 3 (Case 3).
Shots 4, 8, 12 etc are added to Array 4 (Case 4).
Averaged Output displays the averaged value i.e. the total value divided by the number of shots saved in that array ('Set (IQ+1)').
My problems are:
1) I would like to output only the last 4 sets of data from the Averaged Output 1, 2, 3 and 4 to 4 different files (i.e. save as .csv what is displayed onscreen in indicators 'Averaged Output 1', 2, 3 and 4 at the end of all iterations.
Where should I place my file save diagram disable so that it does this?
Putting it outside the main For Loop with auto-indexing on gives me one file with all previous data. (This is not feasible as my number of shots should number in the thousands)
Putting it outside the main For Loop with auto-indexing off gives me only the last set of data. (I need the output for 4 Arrays, not just the last run)
Putting it inside the main For Loop (as shown) gives me the same number of files as number of iterations. (Again not feasible due to large number of files that will be generated and slow camera capture)
For the sake of fast camera capture, I would like these 4 files to only output once all the image captures are complete.
2) Would preferably like to name the file once and for the programme to append '(1)', '(2)', '(3)' and '(4)' to filename of the appropriate 'Averaged Output' Arrays but file path controls are another big headache for me.
3) P.s. is initializing one array enough to avoid using Memory Manager? Or should I initialize 4 arrays?
I am using Labview 2010.
Thanks so much,
Jaslyn
Solved!
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Attachments:
Help Understanding Arrays and file paths (10).vi ‏26 KB

Thanks so much Lennard!!
Hi JKSH,
I've been busy trying to complete the dang code, but for completeness so that other users can learn too, I shall answer your queries. Thanks for looking in.
First, what do you mean by "add"? Your code in your case strcuture sums your input values, so your array size doesn't change. However, you also said "Putting it outside the main For Loop with auto-indexing on gives me one file with all previous data. (This is not feasible as my number of shots should number in the thousands)" -- it sounds like you are expecting an array with thousands of elements. So, what should "Output Array N" look like?
Ans: Output Array N should be a 4x4 array of the summation of all the numbers generated during every 4th iteration.
i.e. if random number 1=1, random number 2=2, etc, And 'No of iterations' is 12,
Output Array 1 should be 1+5+9:
15 15 15 15
15 15 15 15
15 15 15 15
15 15 15 15
(Note: Most of your arrays are 4x4, but in Case #2 you created 128x128. I prersume this is a typo?)
Ans: Kind of, I'm using a 4x4 array of randomly generated numbers as an example but my actual data will be the 128x128 pixel output of a camera. And during actual experimentation, 'No of Iterations' will number in the thousands.
Second, why do you add your "simulated camera input" to the "Initialized Array"? You can add it direcly to the previous output inside your case structure.
Ans: See answer to question 3
Third, have a look at shift registers: http://www.ni.com/gettingstarted/labviewbasics/shiftregisters.htm. Use them instead of Feedback Nodes to make your code tidier.
Ans: I did try.. But I can't seem to add shift registers to the case structure, only the for loops outside. Are you sure it can be done..?
jaslyn wrote:
1) I would like to output only the last 4 sets of data from the Averaged Output 1, 2, 3 and 4 to 4 different files (i.e. save as .csv what is displayed onscreen in indicators 'Averaged Output 1', 2, 3 and 4 at the end of all iterations.
Where should I place my file save diagram disable so that it does this?
For the sake of fast camera capture, I would like these 4 files to only output once all the image captures are complete.
You will need to call "Write to Text File.vi" 4 times to write 4 files. So, you should finish your loop, then call this VI 4 times.
Ans: How do I get it to extract the data from each of the 4 cases in my case structure?
jaslyn wrote:
2) Would preferably like to name the file once and for the programme to append '(1)', '(2)', '(3)' and '(4)' to filename of the appropriate 'Averaged Output' Arrays but file path controls are another big headache for me.
You can create strings first, then convert them into paths: http://zone.ni.com/reference/en-XX/help/371361G-01/glang/string_to_path/
Thanks
jaslyn wrote:
3) P.s. is initializing one array enough to avoid using Memory Manager? Or should I initialize 4 arrays?
I'm not sure what you're asking; can you please clarify what you mean by "avoid using Memory Manager"? But anyway, you've actually initialized FIVE arrays: 1 outside the loop, and 1 inside each case.
I've read that to avoid fluctuations in memory usage, it is a good idea to initialize arrays to their expected size before the start of data collection. That was just what I was trying to do.

Why are date and time strings lost when indexing an array in a for loop

Hi,
I have an application where i'm reformatting data from a spreadsheet for graphical display on a LabVIEW dashboard.
the original spreadsheet has date and time values in separate columns, and i'm merging them and converting to a timestamp value. But something's not working. Does anyone know why the string value is lost when the array indexes into this for loop?
Attachments:
failed array index.png ‏142 KB

Can you attach your VI with some typical values? (e.g. create in indicator on the 2D array, run your VI, then turn the indicator (now containing data) into a diagram constant). Place the FOR loop related code and that diagram constant into a new VI and attach it here.
How many times does the FOR loop run? Could it be that the last element of each 1D array is an empty string? (unless you put a wait inside the FOR loop, you'll never see the other elements in the probe)
LabVIEW Champion . Do more with less code and in less time .

Row operation on array with a For Loop

Hi,
I'm working with a large one dimensional column array. I'm trying to do the following
for i=1:size(A)/2
B(i,: ) =A(1+(i-1)*2:i*2)
So, for example if
A=
0
1
2
3
4
5
6
7
then
B=
0 1
2 3
4 5
6 7
My approach was to use an array subset block inside the for loop to select a number of elements but I'm not sure how to transpose the selected elements into a new row to create the new array B. Is there a more straightforward approach?
Thanks,
Mike
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try experimenting with the reshape array feeding it your input array and re-sizing it to output a 2d aray. It is much faster than using a For loop becuase the data never gets moved and LV just changes the array dimensions and updates the stride.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

How to create parallel tasks using parallel for loops

Hi,
I am setting up a program that communicates with six logic controllers and has to read the system status every 100 ms. We are using OPC datasockets for this, and they appear a little slow.
I have created a uniform comm. method for all controllers, and now I find myself programming this method six times to communicate with each system. I am wondering if this could be done more elegant using the parallel for loop, in which case I would program an exchange once and then have six workers running simultaneously. Since a picture is more clear that a thousand words, what I am asking is this:
Is it possible to replace something like
by
and have this for loop running these tasks in parallel (on different cores / in different threads)?
I have configured the loop to create 8 instances at compile, so I would have 2 instances surplus available at runtime if I find I need an additional system.
The benefits of the method show in the second picture to me are:
* takes less space
* modifications have to be made only once
* less blocks, wires and stuff makes it more clear what's going on.
* flexibility in the actual number of tasks running (8 instances available at runtime)
* if more tasks are required, I need only to update the maximum number of instances and recompile, i.e. no cutting and pasting required.
Unfortunately, I don't have those system available yet, so there's no way to test this. Yet, I would like to know if the above works as I expect - unfortunately the labview help is not completely clear to me on this.
Best regards,
Frans
Solved!
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Dear mfletcher,
First of all: thanks for confirming that my intuition was right in this case.
As for your question on the help: below is a copy/paste from the help on the 'configure parallelism dialog box'
Number of generated parallel loop instances—Determines the number of For Loop instances LabVIEW generates at compile time. The Number of generated parallel loop instances should equal the number of logical processors on which you expect the VI to execute. If you plan to distribute the VI to multiple computers, Number of generated parallel loop instances should equal the maximum number of logical processors you expect any of those computers to ever contain. Use the parallel instances terminal on the For Loop to specify how many of the generated instances to use at run time. If you wire a larger number to the parallel instances terminal than you specify in this dialog box, LabVIEW only executes as many loop instances as you specify here.The reason for me doubting if what I programmed would work the way I intended lies in the fact that the help only mentions processors here, which would be interpreted as actual cores. Thus on a dual core machine, the number should be 2.
I think it would be helpful to mention something about threads here, because in some case one would like to have more parallel threads than there are cores in a system.
In mu case I would like to create six threads, which on my dual core processor would be spread over only two cores. Then these six threads run in parallel.I know that in case of heavy math that would not help, but since I am doing communications, which have timeouts and such, and that probably runs smoother in six parallel tasks even though I only have two cores.
Hope this helps in improving the help of the for loop.
Regards,
Frans

Problem cycling through elements of an array using a for loop ~ error 200609?

Hi,
I'm outputting a 194-element array from a MATLAB script node into a for loop where the array is indexed then converted into a 8-bit boolean pattern which I'm trying to output using DAQ Assistant. I'm using LabVIEW 8.2 and a PCI 6133 DAQ using a counter(Ctr0InternalOutput) to time the output. The first element of the array goes through the loop perfectly however never makes it's way back through and throws error 200609: Generation cannot be started because the slescted buffer size is too small. Increase the buffer size. After probing the line before DAQ Assistant I confirmed only one element makes it through the loop and then throws this error? I've trying doing the same things with lower lowel DAQmx vi's using a DAQmx configure output buffer vi to override this buffer size problem, but still get the same result(not the error but same data flow problem)? Anybody know what's going on? I've included the vi's I've been working with. Thanks!
Millie
Attachments:
Untitled 22.vi ‏228 KB
Untitled 34.vi ‏180 KB

Hi,
I'm outputting a 194-element array from a MATLAB script node into a for loop where the array is indexed then converted into a 8-bit boolean pattern which I'm trying to output using DAQ Assistant. I'm using LabVIEW 8.2 and a PCI 6133 DAQ using a counter(Ctr0InternalOutput) to time the output. The first element of the array goes through the loop perfectly however never makes it's way back through and throws error 200609: Generation cannot be started because the slescted buffer size is too small. Increase the buffer size. After probing the line before DAQ Assistant I confirmed only one element makes it through the loop and then throws this error? I've trying doing the same things with lower lowel DAQmx vi's using a DAQmx configure output buffer vi to override this buffer size problem, but still get the same result(not the error but same data flow problem)? Anybody know what's going on? I've included the vi's I've been working with. Thanks!
Millie
Attachments:
Untitled 22.vi ‏228 KB
Untitled 34.vi ‏180 KB

How to traverse an array with a for-loop in this certain way...

so I need to traverse an array starting from the first element, then from the last element, then the second element, then the second last element, then third element and so on... in a for loop
how would that look in code?
Any help would be appreciated, thanks!
Edited by: inspiredone on Apr 4, 2008 6:34 AM

Wow, that's a really clever and elegant way to do it promethuzz. I actually came up with something already before I read your post so yeah don't worry about me copying or anything. Mine is not as elegant/efficient and I definitely like yours a lot more but I will just share it anyway...it looks pretty similar to the second algorithm The_Matrix has provided. I figured this out from thinking how quicksort compares its pivot with the two indexes...
    int front=0;
    int back = a.length - 1;
    int counter =0;
    boolean switchflag = true;
    while(front<=back)
      System.out.println(a[counter]);
      if(switchflag)
        counter = back;
        front++;
        switchflag = false;
      else
        counter = front;
        back--;
        switchflag = true;
    } Anyways, thanks a lot for you guys help, promethuzz, The_Matrix, and newark.
Edited by: inspiredone on Apr 4, 2008 11:25 AM
Edited by: inspiredone on Apr 4, 2008 11:27 AM

Creating a function with a for loop and %type

Hello,
I am trying to create a function which contains a for loop as well as %type.
This function is on a student table and i am trying to create a function which will display the zip which is a varchar2(5).
I need to do this through this function.
However, I can't seem to get it running.
Can anyone help?
below is what i tried as well as other options and was not successful.
I also displayed my error with the show error command.
SQL> create or replace function zip_exist
2 return varchar2
3 is
4 v_zip student.zip%TYPE;
5 cursor c_zip is
6 select zip
7 from
8 student
9 where zip=zip;
10 begin
11 open c_zip;
12 v_zip IN c_zip
13 loop
14 v_zip:=c_zip%TYPE;
15 end loop;
16 close c_zip;
17 end;
18 /
Warning: Function created with compilation errors.
SQL> show error
Errors for FUNCTION ZIP_EXIST:
LINE/COL ERROR
12/7 PLS-00103: Encountered the symbol "IN" when expecting one of the
following:
:= . ( @ % ;
16/1 PLS-00103: Encountered the symbol "CLOSE"
SQL>
kabrajo

user10873577 wrote:
Hello,
I am trying to create a function which contains a for loop as well as %type.
This function is on a student table and i am trying to create a function which will display the zip which is a varchar2(5).
I need to do this through this function.
However, I can't seem to get it running.
Can anyone help?
below is what i tried as well as other options and was not successful.
I also displayed my error with the show error command.
SQL> create or replace function zip_exist
2 return varchar2
3 is
4 v_zip student.zip%TYPE;
5 cursor c_zip is
6 select zip
7 from
8 student
9 where zip=zip;
10 begin
11 open c_zip;
12 v_zip IN c_zip
13 loop
14 v_zip:=c_zip%TYPE;
15 end loop;
16 close c_zip;
17 end;
18 /
Warning: Function created with compilation errors.
SQL> show error
Errors for FUNCTION ZIP_EXIST:
LINE/COL ERROR
12/7 PLS-00103: Encountered the symbol "IN" when expecting one of the
following:
:= . ( @ % ;
16/1 PLS-00103: Encountered the symbol "CLOSE"
SQL>
kabrajoTry This
Create a sample table
SQL> create table student(id number(10),zip varchar2(5));
Table created.Insert the record
SQL> insert into student values(1111,'A5454');
1 row created.
SQL> commit;
Commit complete.
SQL> select * from student;
        ID ZIP
      1111 A5454
SQL> create or replace function zip_exist(v_id number)
2   return varchar2
3   is
4   v_zip student.zip%TYPE;
5 BEGIN
6   select zip
7   INTO v_zip
8   FROM student
9   where id=v_id;
10   Return v_zip;
11 EXCEPTION WHEN NO_DATA_FOUND THEN
12                  RETURN 'INVALD';
13 WHEN OTHERS THEN
14                 return 'NA!';
15   end;
16 /
Function created.
SQL> set serveroutput on
SQL> select zip_exist(1111) from dual;
ZIP_EXIST(1111)
A5454
SQL> select zip_exist(2222) from dual;
ZIP_EXIST(2222)
INVALDHope this helps
Regards,
Achyut K

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