Determining array size

How can I tell the size of an array? Is there a function? Do arrays automatically contain a '\n' or anything as their last element? I have a for loop that needs to process each element in the array, but it needs to know when to stop.

if you declare the following array:
int array[] = {1, 2, 3, 4, 5,};
the following would get the length:
int length = array.length;
length would then equal 5. remember not to end the array.length statement with () ( array.length() ) as this is how you get the length of a string. a little fyi, pick up the book, Java 2 Black Book by Steven Holzner, the best java book i've seen, good reference, hope this helps.

Similar Messages

How do I determine array size in a formula node

I am feeding an array into a formula node to perform an operation on. However the size of the array can be an arbitrary size. How can I determine its size to use for iterating through a for loop?
I suppose that I could add another input that is fed with the array size from the array palate but I would like to know if it can be done inside the formula node itself.

Your own advice is the only and best one.
greetings from the Netherlands

Determination of array size in bytes

Dear forum users,
I want to determine the size of an array subset in bytes.
At the moment I try to do this as shown in my attached program: Simply said, I am reading in my data (example data can also be found in the attachment) and convert them into an array. From this array I am taking the subset I am interested in. This array subset is saved in a new file from which I determine the byte size with the “Get File Size.vi”.
That are a lot of steps with file saving (deletion of the compulsory created new file not mentioned) just to get the byte size of this array subset. And with this approach the file size (the byte size of my array subset) is unfortunately depending on the format with which I save the file (%.6f or similar), but I would need the byte size of this subarray as it would be in the original file (see my comment on the front panel).
Therefore, I want to know if there is a better, simpler, quicker and correct way to get the byte size of a subarray.
I would be very happy about every comment and help!
Attachments:
ByteSizeOfArraySubsetLV2011.vi ‏18 KB
ByteSizeOfArraySubsetLV8_6.vi ‏15 KB
ExampleData.txt ‏1114 KB

Dear GerdW and smercurio_fc,
Thanks a lot for your replies! Perhaps I should have mentioned that I need the size of my array (string…, I am confused now) in bytes because I want to use later in my program the “Set File Position.vi” (which needs an offset in bytes). With this vi I want to read in my data again but starting after the data which I have used in my array (I try to make bunches out of my file).
Ok, the suggestion of GergW is a step forward, but it does not work correctly. I have modified my program a bit (see attachment), so that it gives back the file size of the original file and the length of the string after the file has been read in. Interestingly, the numbers are not the same. The same is also true for my subarray (and the string length is still dependent on the format with which I convert my array to a string).
So once again asked: If I take from my original file lines 3 to 12, copy them in a new file and save this file, then I can read out the size of the file (191 bytes). How can I get the same number in LabVIEW after reading in the original file and taking the same subarray? I hope my question is clearer now (it is surely suffering a bit from my bad English. I am sorry!).
I hope to hear from you again!
Attachments:
ByteSizeOfArraySubsetLV2011_2.vi ‏14 KB
ByteSizeOfArraySubsetLV8_6_2.vi ‏11 KB

Oracle DBSL - Determine / Define size of fetch array

Hello guys,
i have a question about the Oracle DBSL and how it determines the size of the fetch array.
I am refering to the following documents / documentations:
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/86a0b490-0201-0010-9cba-fd5c804b99a1
Quote:
As long as you do not program an UP TO ROWS in ABAP, the database gets as many table rows as possible per communication set (as many as fit in 32k).
http://help.sap.com/saphelp_nw04/helpdata/en/d1/801f96454211d189710000e8322d00/frameset.htm
Quote:
You have to specify the size of an array before runtime. However, because you cannot know the size of the dataset the system will return, you must define a very large array to avoid an overflow.
To circumvent this problem, the SAP Basis System translates ABAP Open SQL statements into Embedded SQL. To do this, the system defines a cursor.
Ok but the translated embedded SQL code has also to specifiy an array fetch size (how many rows are retrieved by one fetch).
Is this a profile parameter or is it really calculated (how many rows of a specified table would fit into 32k) dynamically in the DBSL?
Regards
Stefan

Hello Michael,
i am refering to the documentation of DEFAULT_SDU_SIZE:
> Use the parameter DEFAULT_SDU_SIZE to specify the session data unit (SDU) size, in bytes to connections.
> session data unit (SDU)
>A buffer that Oracle Net uses to place data before transmitting it across the network. Oracle Net sends the data in the buffer either when requested or when it is full.
Ok, that controls the transmit moment in the network layer.. but not the number of rows which are returned by a single FETCH call (through the OCI). (For example in sqlplus it can be set with set arraysize XX)
I have tested also a little bit around with different sap standard tables in an ERP 2005 system.
I have activated a SQL Trace (ST05) and done a "select * from <TAB>" via SE16 (no count limit!).
In my tests there were fetched different number of rows - take a look by your own:
Time Object    Operation Rows   Returncode
2.451 T100       FETCH     321      0
1.915 T100       FETCH     321      0
1.912 T100       FETCH     321   1406
1.246 E071K      FETCH     109      0
1.218 E071K      FETCH     109      0
1.155 E071K      FETCH     109      0
T100 (4 VARCHAR columns)
E071K (14 columns of different types)
So it seems like the DBSL dynamically calculates the number of rows which can be returned by a single fetch call based on the row size (number of columns and column sizes) and other unknown factors.
If this is true, it would be really great and nothing have to be done by us (the customers!).
But if the DBSL dynamically calculates the max. number of rows per fetch:
Why is a "SELECT * FROM <TAB> INTO <ITAB>" preferred - the SELECT Statement in a LOOP (like in the example) is also fetching the max number of rows by each fetch, or?
The example: http://sap.mis.cmich.edu/sap-abap/abap04/sld017.htm
That was only a notice on some small tests, which i have done.. maybe someone knows it in detail.
Regards
Stefan

How Can I Determine the Size of the 'My Documents' Folder for every user on a local machine using VBScript?

Hello,
I am at my wits end into this. Either I am doing it the wrong way or it is not possible.
Let me explain. I need a vb script for the following scenario:
1. The script is to run on multiple Windows 7 machines (32-Bit & 64-Bit alike).
2. These are shared workstation i.e. different users login to these machines from time to time.
3. The objective of this script is to traverse through each User Profile folder and get the size of the 'My Documents' folder within each User Profile folder. This information is to be written to a
.CSV file located at C:\Temp directory on the machine.
4. This script would be pushed to all workstations from SCCM. It would be configured to execute with
System Rights
I tried the script detailed at:
http://blogs.technet.com/b/heyscriptingguy/archive/2005/03/31/how-can-i-determine-the-size-of-the-my-documents-folder.aspx
Const MY_DOCUMENTS = &H5&
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objShell = CreateObject("Shell.Application")
Set objFolder = objShell.Namespace(MY_DOCUMENTS)
Set objFolderItem = objFolder.Self
strPath = objFolderItem.Path
Set objFolder = objFSO.GetFolder(strPath)
Wscript.Echo objFolder.Size
The Wscript.Echo objFolder.Size command in the script at the above mentioned link returned the value as
'0' (zero) for the current logged on user. Although the actual size was like 30 MB or so.
I then tried the script at:
http://www.experts-exchange.com/Programming/Languages/Visual_Basic/VB_Script/Q_27869829.html
This script returns the correct value but only for the current logged-on user.
Const blnShowErrors = False
' Set up filesystem object for usage
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objShell = CreateObject("WScript.Shell")
' Display desired folder sizes
Wscript.Echo "MyDocuments : " & FormatSize(FindFiles(objFSO.GetFolder(objShell.SpecialFolders("MyDocuments"))))
' Recursively tally the size of all files under a folder
' Protect against folders or files that are not accessible
Function FindFiles(objFolder)
On Error Resume Next
' List files
For Each objFile In objFolder.Files
On Error Resume Next
If Err.Number <> 0 Then ShowError "FindFiles:01", objFolder.Path
On Error Resume Next
FindFiles = FindFiles + objFile.Size
If Err.Number <> 0 Then ShowError "FindFiles:02", objFile.Path
Next
If Err.Number = 0 Then
' Recursively drill down into subfolder
For Each objSubFolder In objFolder.SubFolders
On Error Resume Next
If Err.Number <> 0 Then ShowError "FindFiles:04", objFolder.Path
FindFiles = FindFiles + FindFiles(objSubFolder)
If Err.Number <> 0 Then ShowError "FindFiles:05", objSubFolder.Path
Next
Else
ShowError "FindFiles:03", objFolder.Path
End If
End Function
' Function to format a number into typical size scales
Function FormatSize(iSize)
aLabel = Array("bytes", "KB", "MB", "GB", "TB")
For i = 0 to 4
If iSize > 1024 Then iSize = iSize / 1024 Else Exit For End If
Next
FormatSize = Round(iSize, 2) & " " & aLabel(i)
End Function
Sub ShowError(strLocation, strMessage)
If blnShowErrors Then
WScript.StdErr.WriteLine "==> ERROR at [" & strLocation & "]"
WScript.StdErr.WriteLine " Number:[" & Err.Number & "], Source:[" & Err.Source & "], Desc:[" & Err.Description & "]"
WScript.StdErr.WriteLine " " & strMessage
Err.Clear
End If
End Sub
The only part pending, is to achieve this for the 'My Documents' folder within each User Profile folder.
Is this possible?
Please help.

Here are a bunch of scripts to get folder size under all circumstances. Take your pick.
https://gallery.technet.microsoft.com/scriptcenter/site/search?query=get%20folder%20size&f%5B0%5D.Value=get%20folder%20size&f%5B0%5D.Type=SearchText&ac=2
¯\_(ツ)_/¯

How do I determine the size of an object?

After an object is instantiated, is there anyway to determine its size (in bytes)?

Why do you want to know? Java handles memory management for you.
IIRC for Sun JVM 1.4:
Objects: four bytes for each reference, boolean, byte, short, int, float or character field, eight bytes for each long or double field, plus sixteen bytes header information.
Arrays: length * (four for reference, int or float; one for boolean or byte; two for short or character; eightfor long or double), plus sixteen bytes header information.
Pete

How to adjust a "control array" size

I have a program that creates a digital PWM signal with variable duty cycle. The duty cycle changes every 50 ms, but the overall wave frequency stays at a frequency determined by the user. I have the VI attatched.
My problem is this...I need to be able to control the overall cycle time. This means the size of my array of duty cycles needs to adjust based on the cycle time (i.e. a cycle time of 1 second would require 20 of the 50 ms slots, while a 1.3 second cycle would need 26).
I currently have only 4 slots in my array, meaning the total cycle time is .2 s. I understand how to manually add and remove elements to the array, but I can't figure out how to add a control to it so that the array size changes automatically, allowing much quicker entry of data. As of now I can make it work, it just takes super long to add or delete array elements. The ideal situaton would have a constant control for cycle time divided by 50 that would change the array size.
I can't find any info on this, and I think I even saw a post asking that this kind of feature be added. I'm relatively new to this program.
Thanks
Solved!
Go to Solution.
Attachments:
var_duty_cycle.vi ‏25 KB

Currently, your VI is a one-shot deal. What you need is a state machine that updates the pct duty cycle array control as a function of the frequency while the current I/O code is idle.
I would use an array of clusters, where each cluster contains e.g. a sequence number, a duty cycle, and a string as element label. Show the scrollbar and set the size whenever the relevant inputs change. Do you want to reset the current setting when the number changes or do you want to retain the current settings as much as possible? You could just use the existing values, reshape to the larger or smaller size, and write it back to the control via a local variable. Set all elements except the percent to disabled so they act as indicators and cannot be changed by the user.
(You also need to program around it if the operator tries to manually add more elements. A better solution would be this idea, so vote for it .)
Some more general comments bout your code:
Why do you use extended precision floating point. All your waits are internally just integers. EXT makes no sense
There is a primitive for 1/x. However, you could just do a 1000/x and eliminate the multiplication afterwards. SInce you are dealing with integers, you can even do the division using quotient&remainder. Depending on the allowed frequency range there are possibly no orange data needed at all.
Make the diagram constant representation match the rest of the code.
The pulses/50ms indicator belongs before the loop. No need to recalculate and refresh it over and over from the same input values.
LabVIEW Champion . Do more with less code and in less time .

How to generate a csv report to determine paper size in a pdf or pdf/a file ?

how to generate a csv report to determine paper size in a pdf or pdf/a file ?

Use the cfpdf tag as follows:
<cfpdf
    action = "getinfo"
    name = "pdf_info"
    source = "C:\temp\testFile.pdf">
My Operating System is Windows. This tag gets information about testFile.pdf, and stores it in a structure. I have given this structure the name pdf_info. This structure has the key you are interested in, namely, pageSizes.
Pdf_info.pageSizes is an array whose indices correspond to the respective page number in the PDF. You can use this to generate Comma-Separated Values (CSV) for each page.

<cfset csv = "">

<cfset csv = "Page,Height,Width" & chr(13)>
<cfloop from="1" to="#arrayLen(pdf_info.pageSizes)#" index="i">
<cfset row_info = i & "," & pdf_info.pageSizes[i]["height"] & "," & pdf_info.pageSizes[i]["width"] & chr(13)>
<cfset csv = csv & row_info>
</cfloop>

<cfoutput>#csv#</cfoutput>


Done!

Two instances of quirky behavior: array size of empty array and tab control freeze

LV 7.1
Array size of empty array. Adding empty arrays to an array of higher dimension produces a fantom array of non-zero size.
Tab control freeze. An event structure with checked 'lock front panel until the event case completes' option permanently freezes the front panel in certain special circumstances.
Zador

tst wrote:
Tell me if you still think this makes sense.
Whew, let me look at this tonight after I activate the 4D module in my brain.
(I think it makes sense, though ) Generally I look at the product of the dimensions array to determine if an array is empty. You can initialize a multidimensional array with some dimensions at zero and it is reproduced nicely in the array size output. Also the "Empty array" tool correctly identifies it as empty, even if some dimensions are nonzero.
Message Edited by altenbach on 03-15-200612:42 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
init.png ‏3 KB

Array size in Analog Tacho Processing vi

Hi
I would like to know more about what Analog Tacho Processing vi does particularly on the array size that it generates.
Attached is an example of vi that comes with LabVIEW. I used the array size function to show the size of the signal before passing thru the Analog Tacho Processing vi, and after the signal passes it. When we run the PC fan runup.dat file (which can be found in the LabVIEW order analysis Example Data), we can see that the array sizes for before and after passing thru the Analog Tacho Processing vi are 58368 and 1455, respectively. What I would really want to know is how the 1455 is generated.
Any help is greatly appreciated.
Thanks
Attachments:
Getting Started Exercise_Order Analysis.vi ‏330 KB

Since the Express VI calculates rotational speed based on pulses per revolution, it will use those pulses to calculate the speed profile. For example your input waveform may have 1000 data points to describe 3 pulses, the VI is going to just use those 3 physical pulses to determine rotational speed (based on the value you set for pulses per revolution). Thus you will never see the same number of points on the input and output of this VI. If you are trying to determine the exact formula it is using I will not really be able to help you with that.
My best suggestion would be to use context help and the detailed help for that VI, you can also right click and open the front panel of the Express VI if you are so inclined.
Happy Programming!
Kyle
Applications Engineer
National Instruments

Given array control reference, how do I obtain array size programatically

If an array control reference is passed to a sub-vi, how do I obtain the current length of the array within the sub-vi? I've tried two properties: "NumRows", which as documented, contains the visible number of rows in the array control. "IndexVals" contain the indices of the array element in the upper left corner of the array control. There seem to be no methods for obtaining the current array length. I tried changing the class of the array reference to cluster then using the "Controls[]" property... but this generated a runtime error. What am I missing? Thanks.
Solved!
Go to Solution.

Taki1999 wrote:
There's a lot of casting going on in your subvi.
What is the actual use case? There might be a way to do this which doesn't require the casting and you could work just with the reference that is passed in.
For your method you need to wire in a strict class specifier into the To More Specific Class conversion. I'm not sure how to make the strict class specifier.
I can help with that but first...
Working with arrays on unknown data types is no esy task and determining the size is a special challenge and I did just that in this Nugget that talks about using control references. This task is much easier when you know at development time what is in the array. That is where the strict type casting comes into play.
What I would do...
1) Make sure the contents of the array is a type def (to support data strcuture changes in the future).
2) Go to the FP of the VI that has the array in question and drop a generic control ref control.
3) Ctrl-copy and drag the array in question INTO the the generic ref (still working on the FP). You can tell when you find the "sweet spot" in the ref control because it will switch it appearence. See this mini-nugget for an image where the same thing can be done with que refs.
4) Make the now strict ref a type def.
5) Use the type-def'd ref from step #4 in the sub-VI as the proptype used by the "To More Specific...."
After those changes you should be able to work with array in the sub-VI as if it were in the top level.
BTW:
Doing the above on the control in the sub-VI that brings in the ref would allow skipping the "To more Specific..."
Have fun!
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Data type of preprend array size in Flatten To String block

Hi
The data type of the preprend array size in Flatten To String block is given as I32. Is it somehow possible to reduce the data type to I8, since the width and height of my array won't exceed 255 ?. I also need to do the same in Unflatten To String as well.
Best regards
Oesen

Oesen wrote:
Hi
The data type of the preprend array size in Flatten To String block is given as I32. Is it somehow possible to reduce the data type to I8, since the width and height of my array won't exceed 255 ?. I also need to do the same in Unflatten To String as well.
The short answer is no. This is because the index is an I32. NI likes to keep integers as an I32 whenever possible for reasons like this.
Since you are dealing with a 2D array (width and height), it will actually use 2 I32s before the actual data.
As Ravens stated, you could put in your own array sizes before the array in the string. But it is worth saving 6 bytes? Not likely.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

How to determine the size of an InputStream??

Hello,
I need to get the size of an inputstream. In fact, I am working with java.nio.channels and need to tranfer a file from within a Jar to the FileSystem.
I have created a ReadableByteChannel from the jar resource, and a FileChannel from the FileSystem destination. The problem is that to use the FileChannel .tranferFrom(..) I need the size of the src file. But, ReadableByteChannel has no size() method.
How can I determine the size of this InputStream??
advanced Thanx
here is code:
private void copyResourcesToFileSystem(){
          try{
                    String name = getFileName(); // gets the name
                    ReadableByteChannel srcChannel =
                         Channels.newChannel(this.getClass().getClassLoader().getResourceAsStream(("dtd/"+name)));
                    File newFile = new File(TempDirCreator.getXmlDir(),name);
                    FileChannel dstChannel = new FileOutputStream(newFile).getChannel();
                    dstChannel.transferFrom(srcChannel, 0, srcChannel.size()); // doesn't work -- there is no ReadableBC.size()
                    // lets close the show
                    srcChannel.close();
                    dstChannel.close();
          }catch(IOException x){x.printStackTrace();}
          catch(Exception ex){ex.printStackTrace();}
     }

In general the "size of an InputStream" is a meaningless concept. It's possible to have an InputStream that never terminates. So if you can't get a size from whatever you're reading from, you're out of luck.
I missed where you explained why you need the size. I've never felt the need to know how many bytes would be passing through my code when copying from input to output.

How to determine the size (in pixels) of the current mode

Hello.
I am looking for a was to determine the size (horizontal and vertical pixels) of the current mode (SAPGUI window). I have already looked through the methods provided by class CL_GUI_CFW...
CL_GUI_CFW=>GET_METRIC_FACTORS provides the size of you display (i.e. 1600 x 1200 pixels) and some other information I am not able to interprete.
Futhermore I have had a look at the Methods CL_GUI_CFW=>COMPUTEPIXEL, but I don´t know how to use them.
Has anybody of you any experiences in this topic? I would be grateful ...
MIKE

Sorry Manoj,
but i didn´t find out, why these programs should be able to solve my issue. They just display a picture using the CL_GUI_PICTURE control.
I am looking fo a way to resize a given control to the very maximum, so that it fills the whole SAPGUI window!
Thanks anyway...
MIKE

Change array size and delete duplicate row

Hello,
I am running a program that does a for loop 3 times. In each loop, data is collected for x and y points (10 in the example provided). How can I output the array with the 30 points in a simple 2D array (size 2x30)?
Also, from the array, how do I delete duplicate rows that contain the same x-value?
Thanks,
hiNi.
Solved!
Go to Solution.
Attachments:
array size.vi ‏10 KB

Hello,
THANK YOU for solving my first issue! Attached is the data set that contains the duplicate entries for the x-axis values. The y-axis value may be different, but not the x. I would like to delete the 2nd row that contains the same x-value.
Here is simple example of my input and desired output:
IN:
28.512000 -115.310532
28.812000 -86.937660
29.112000 -116.877052
29.412000 -87.223625
29.412000 -111.349045
30.012000 -86.510780
30.312000 -112.048187
OUT:
28.512000 -115.310532
28.812000 -86.937660
29.112000 -116.877052
29.412000 -87.223625
30.012000 -86.510780
30.312000 -112.048187
I am thinking of comparig the last x-axis value to the current one, and if it is the same, then not parse that row. The attached VI is as far as I got.
Any help will be greatly appreciated.
Thanks,
hiNi
Attachments:
delete duplicate row.vi ‏8 KB
data.txt ‏1 KB

Determining array size

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