Empty array of unknown size in formula node

I have to declare an empty array say, P of unknown size in formula node. How to do that?

Hi sukhiray,
an empty array has a known size...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Similar Messages

Error unsupported memory access on variable 'Decoder.number_of_values' which is (or contain) an array with unknown size at compile time

Dear All,
I am a new user of Vivado HLS. I want to pass an array of struct to a function and use elements of struct multiple times in a function (read and write). I find this error "error unsupported memory access on variable 'Decoder.number_of_values' which is (or contain) an array with unknown size at compile time " . Kindly can anyone tell that is it an issue of directive? if yes then which directive to use for struct and its element. Struct and function are as follows.
typedef struct {
uint32_t number_of_values ;
uint32_t address[16];
uint8_t Processed_bit :1 ;
uint32_t links[6];
} Decoder_Fields;
void Raptor_LT_decode(int To_Send,Decoder_Fields *Decoder){
   int counter=0;
   int i=0,j=0,k=0,x,aaa;
   Raptor_LT_decode_label0:while(counter<To_Send){
       if((Decoder[counter].number_of_values ==1) &&(Decoder[counter].Processed_bit==0) ){
           Decoder[counter].Processed_bit=1;
           Raptor_LT_decode_label1:for (i=0; i<To_Send;i++){
               Raptor_LT_decode_label2:for (k=0;k<Decoder[i].number_of_values;k++){
                   if (( Decoder[counter].links[0]==Decoder[i].links[k]) && (counter != i)&&       (Decoder[i].number_of_values!= 1)) {
                       Raptor_LT_decode_label3:for (j=0;j<BLOCK_SIZE_BYTES/4;j++){
                               Decoder[i].address[i]= Decoder[i].address[j] ^ Decoder[counter].address[j];
                       for (x=k;x<Decoder[i].number_of_values-1;x++) Decoder[i].links[x]=Decoder[i].links[x+1];
                                  Decoder[i].number_of_values--;
           counter=0;
       else
           counter++;

Hi ,
This question is asked on the forum from time to time and should be described in the UG902
In your top level, Decoder is a pointer; this is not supported as-is as you need to know its size when you do something like Decoder[i].XXXX : the tool need to know how many bits to size the addess bus.
you need to change Decoder_Fields *Decoder to Decoder_Fields Decoder[YOURSIZE]
with YOURSIZE that makes sense; in this case the tool will know that it need N=log2(YOURSIZE) to fully address the Decoder array variable.
next when you solve that and that all is good... the question that you will need to transfer the data of the structs from host memory to your VHLS IP; you need to think about this.
I hope this helps.

Formula node for array

hi
i want to convert the values of an array using a different formula for each value in the array. Can i use formula node for this? if yes how
if no then is there any other method except for extracting each one individually and converting?

kunal227 wrote:
there are 16 elements in the array and the number remains constant (actually they are temp values acquired by a fieldpoint hardware).
the formula is a linear conversion (for example y = m*x + C) corresponding to the calibration curve of individual thermocouple connected to the fieldpoint hardware. every thermocouple has a different calibration curve and hence every element in the array is converted using a different linear formula.
All you need is an array of [m] and an array of [C], all the same size as your data arrray. No formula node needed.
(I think that's what mikeporter had in mind above)
Message Edited by altenbach on 07-24-2007 03:38 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
CorrectedArray.png ‏4 KB

Array init in formula node

I would like to cut and past in a list of comma seperated numbers and initialize an array of float32. Something like this would work in C.
float32 data[5] = {0,1,2,3,4};
Labview does not like this syntax when using a formula node. I have to do the following instead
float32 data[5];
data[0] = 0;
data[1] = 1;
What is the correct syntax for initializing arrays in lavview using a formula node. I would be amazed if Labview does not have this basic functionality.
thanks in advance
jim bob

labview_noob wrote:
ttt, no one?
Probably because we are using LabVIEW to get away from text based code.
(I don't know if there is a syntax for the formula node, it's been too long. )
If you have LabVIEW 8.0 or higher, you can use matlab like sytax in a mathscript node. Of course you could just paste your list into a string constant and get the values with "spreadsheet string to array".
Message Edited by altenbach on 07-25-2007 12:24 AM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
ArrayFormula.png ‏13 KB

Formula node problem

Basically I initialize an array and then run a formula node which fills up an array based on the cells that are written in the first frame of the sequance to that array. My problem is that it appears that the formula node does not actually write anything to my array table. I ran multiple simulations but was not able to explain this problem. Please see the sequance structure at the bottom of my code.
Attachments:
Spektr.vi ‏47 KB

Your Timeout case may be empty, but since you're wiring a constant of 10 to the Event Structure's "Event Timeout" the Event Structure will trigger every 10 msec even if there's nothing to do. If you left the "Event Timout" unwired the event structure will trigger only when there's an actual event.
There are numerous examples that ship with LabVIEW. Open the Example Finder (Help -> Find Examples), and then in the tree menu select "Fundamentals -> Arrays and Clusters". You should start with the example "Building Tables", as this is what you really want to do. Basically, all you're doing is adding some columns to a pre-existing array. Your implementation of the formula is not correct to begin with since you only get one value out, and I'm guessing you want to generate those additional "Harmonic" columns. The best/easiest way to do this is with an autoindexed loop. Here is one way to do this:
Also, in regards to your statement
also if I use the flat sequence instead of the
stacked one will that write the Value after each frame instead of
writing only after the end of the whole sequence structure?
The answer is no, if you keep the tunnel and property nodes in the same way. The type of sequence frame doesn't matter. It's when the data is available.
Message Edited by smercurio_fc on 05-27-2008 03:29 PM
Attachments:
Example_VI.png ‏15 KB

Can the Property Loader load arrays of variable size?

I need to run a series of tests on the same UUT, changing only one parameter at a time (for example, a frequency response test). The hardware developers would like to be able to change the values of parameters of the test at will, without making changes to the sequence. That's easy - just change the value of the parameter in the Properties file. The hard part is changing the number of iterations of the test, by ONLY adding or deleting the number of parameters from the text file. In other words, all I know during sequence editing is the types of parameters, not the values or how many. I want the test to loop as many times as there are sets of parameters in the text file.
I would like to do this by loading the paramet
ers as an array. But the Property Loader wants me to specify each variable while I am editing the sequence, including each individual member of the array (e.g. "Locals.Array[0].Value"). I want to do somthing like "Locals.Array[*].Value", where "*" means "all elements".
Am I forced to write external code to load each parameter, or does TS have a native way to do this? Even better, has anybody done this already, and will you explain how? Thanks

Hi,
there's a couple of options here, and I've included what I think is the simplest below (using TestStand 2.0.1).
It's not exactly elegant though. What I've done is to put in a step that finds out the number of steps to load (based on an earlier decision - in this case a message popup step). I read a number from the limits file, and use this in the looping options of the property loader step that's loading the values into the array. I've done it with a fixed size array target here, big enough to take any incoming data. (Otherwise, knowing how many items you're going to load from the limits file, you could start with an empty array and re-size it prior to loading).
I've cheated slightly by using the pre-expression on the property loader step to specify where th
e data is coming from and where it's going to in the sequence on each iteration of the loop based on the Runstate.Loopindex.
Another option is to go straight into the property loader step, and keep loading properties until the Step.Result.NumPropertiesRead = 0 (remember we're only doing this one at a time)
Another idea would be to load in a value, and check it isn't a "flag" value (i.e. you'd never use say 999 in your array, so set the last element in your limits file to this, and drop out of the loop when this happens.
Further still, you've got the source code for the property loader step, so you could re-write it to make a custom step that loads an array until it fails all on its own (no looping in TestStand).
Hope this gets you going
S.
// it takes almost no time to rate an answer
Attachments:
DynamicPropertyLoader.seq ‏32 KB

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

Array output from formula node with input variable as array size

Hi,
I have created a formula node with an array output called al, but I get an error "you have connected a scalar type to an array with that type".
I declare the output as follows..
float64 al[len_as];
where len_as is an scalar input to the formula node.
It only works when I put a number as.
float64 al[5];
,but I don't know beforehand how many elements I need, so I cannot use this.
Please help! This is so stupid.
Thanks

Don't define your array in your formula node.
Initialize the array as the size you want and pass it in as an input into the formula node.
Are you sure you even need to use a formula node? Can you implement your formula using all native LabVIEW functions?
Message Edited by Ravens Fan on 10-07-2009 11:51 PM
Attachments:
Example_VI_BD.png ‏3 KB

Formula Node: Array Size can be specified by wiring an input ?

All
I have a formula node where I have a module which operates on an array. I want to keep the size of the array generic. So I tried keeping the array size as an input N, and initialized the array as xdim[N]. It shows an error in my formula. what am i doing wrong ?
Kudos always welcome for helpful posts

I had exactly the same issue as Spartan00.
Just for curiosity, I was comparing labview speed in initializing a gaussian array through both the normal graphic code and the formula node.
The formula node proved to be MUCH, MUCH faster.
float m = 0.5, s=0.5, x;
int i;
float y[1000000];
for(i=0; i<1000000; i++) {
x=i*1e-6;
y[i]=exp(-pow((x-m),2)/(2*s));
Unfortunately, I can't wire the array size as an input.
(By the way, I simply enclosed the formula node in a for loop and let it run 10000 times to get the average execution time. I did the same for the equivalent graphical code and it turned out to be much slower).
Has anybody ever tried to do the same?

Can I create array inside formula node

I need to create and use array (multidimensional) inside a formula node. My LabVIEW version is 5.1.The input and output from/to formula node do not necessarily being array. Thank you.

You need to declare a variable to be an array. To declare a multidimensional array of 32 bit intergers enter this:
int32 VarName[x][y];
Where x=1st dimension size (rows) and y=2nd dimension size (columns). You can then operate on this like you would an array in a text based language. Try the entering the example below in a formula node.
int32 i;
int32 y[5][2];
for (i=0;i<5;i++)
y[i][1] = x[i]+1;
Where y is an output and x is an 1D array input.
Hope this helps...
Brian

Array index problem in formula node

dear friend
I'm trying to use formula node to solve a problem because I make this program using c at the begining.
It runs perfectly in turbo c, but somehow it doesn't work in the formula node.
I try to debug my source code, and I find that the formula node seems can't read the true value in
the array.
Here is the code in the formula node.
int32 i,j,k;
for ( i = 0 ; i < sopa; i++ )
j = 1;
ep[i][0] = pa[i];
ep[i][1] = np[ep[i][0]][0];
while ( ep[i][j-1] != exit )
  for ( k = 0 ; k < sonp ; k++ )
    if ( np[ep[i][j-1]][k] != -1 && (pc[ep[i][j-1]][ep[i][j]] + pc[ep[i][j]][exit] >= pc[ep[i][j-1]][np[ep[i][j-1]][k]] + pc[np[ep[i][j-1]][k]][exit] ) && (pc[ep[i][j-1]][np[ep[i][j-1]][k]] == org[ep[i][j-1]][np[ep[i][j-1]][k]] ))
      ep[i][j] = np[ep[i][j-1]][k];
  j++;
This is the part that I think the problem might be.
if ( np[ep[i][j-1]][k] != -1 && (pc[ep[i][j-1]][ep[i][j]] + pc[ep[i][j]][exit] >= pc[ep[i][j-1]][np[ep[i][j-1]][k]] + pc[np[ep[i][j-1]][k]][exit] ) && (pc[ep[i][j-1]][np[ep[i][j-1]][k]] == org[ep[i][j-1]][np[ep[i][j-1]][k]] ))
ep[i][j] = np[ep[i][j-1]][k];
I state that "np[ep[i][j-1]][k] != -1" but I do get the value -1 in the array "ep".
Could someone tell me why I get -1 in the array?
I hope I can finally do it all by labview not using formula node,but array like "pc[ep[i][j-1]][np[ep[i][j-1]][k]] "
seems very hard to wire in labview. Could someone give me some good advices of doing this?
Thanks for your help

altenbach 已寫:
normanshi wrote:
ep[i][0] = pa[i];                                          (A)
ep[i][1] = np[ep[i][0]][0];                            (B)
...    if ( np[ep[i][j-1]][k] != -1 && ... )          (C)
      ep[i][j] = np[ep[i][j-1]][k];                       (D)
I state that "np[ep[i][j-1]][k] != -1" but I do get the value -1 in the array "ep".
Could someone tell me why I get -1 in the array?
I hope I can finally do it all by labview not using formula node,but array like "pc[ep[i][j-1]][np[ep[i][j-1]][k]] "
seems very hard to wire in labview. Could someone give me some good advices of doing this?
There are many possible scenarios to get a -1 in the ep output. For example if the -1 gets already written in step (A) or (B) at a certain index, and that index does not get overwritten in step (D). You are indexing all over the place! Is there some bounds checking on the array contents? What are typical inputs and array sizes?
I'm sure about that the -1 doesn't get already written in step (A) or (B) because ep[i][0] and ep[i][1] is fine. What really makes me confuse is that sometimes ep array has the value like this.
That means it does overwritten some value in step (D). The -1 should never be written into it because I have already state that np[ep[i][j-1]][k] != -1. Somehow I still get -1,and this is really strange! I'm indexing all over the place becuase I can't figure out a better way to achieve my requirement.
I think I should briefly tell you what I'm trying to do. In this program,I input some values which means the distance from one point to another. Then I use floyd's all pairs shortest-path algorithm to find all the shortest distance. Finally I want to find out the "shortest path". I mean like from point 4 to point 0,the shortest path might be like 4 -> 2 -> 1 -> 0, and what the formula node part do is trying to find out this "shortest path". Maybe you can give me some better advice of doing this, I have been thinking a better way to do it for about two months. I think I'm really not good at this.
I try to do it all by labview ,but again I get a strange problem. This time the ep[i][j-1] doesn't get the correct value. In the first time i=0 j-1=0 ep[i][j-1] = 1,but the second time i = 0 j-1 = 1 ep[i][j-1] = 0. This makes the "ep[i][j-1]!=exit" get the incorrect boolean value. The ep[i][j-1] should be 2,not 0. I try to use highlight to find if I make any mistake, but I can't one.This is the input and I put the labview program in attached file (temp4.vi).
Could you help me find out why this happened?
Thanks for your help altenbach!
由 normanshi 在 08-19-2006 10:06 PM 上編輯的訊息
Attachments:
temp4.vi ‏191 KB
ep.jpg ‏10 KB
input.jpg ‏9 KB

Array Handling in Formula Node

I have attached a simple VI wherein I want to take an input array, look at its size and use the size of the input array as the size of the output array. The output array needs to be declared. I want to be able to use the size of the input array "N" as the size of the output array too. The size of the input array changes dynamically based on my simulation needs. I dont want to modify the size of the array in the declaration every time I change the array size in simulation.
I have tried using b[N] instead of b[10] in the formula node. However LV does not seem to accept this and gives me a syntax error.
Attachments:
Array Handling in Formula node.vi ‏8 KB

AGovi wrote:
However I require to use complicated formulas such as
If a simple formula is easier in G, a complicated formula will also be easier in G.
Actually, it will scale better. Since graphical code is 2D, doubling the code will make it only 1.4x (sqrt2) larger in each dimension, while the formula will double in lenght.
LabVIEW Champion . Do more with less code and in less time .

How do I get an array output on a Formula Node?

My problem is simply that I cannot figure out how to get an output on a Formula Node to be an array. Documentation states that "you must declare local arrays and output arrays in the Formula Node" but doesn't say anything more than than. Attempts to put something like "float32 out[100];" for an array output called "out" fail.
If anybody knows how you can do this or even knows if it is possible I would appriciate your help.
Thanks,
Naveen

I found a typo in the formula node I was doing that was making the output not be an array. I don't think I was getting the error before but I was going to put together an example VI to attach here and I found it. So, thanks for your help even tho it was a stupid little mistake on my part.

How can I increment the index of an array in a formula node?

Hi,
I need some help with the formula node. I need an array, that increment every iteration of the code in the formula node. I need it to save amplitudes.
I thought i could do this with i++; i is the variable for my index.
Martin
Solved!
Go to Solution.

Hello,
does it sound well to you ?
@+
Tinnitus
ps: sorry posts mixed
Message Edité par tinnitus le 12-15-2008 03:05 AM
CLAD / Labview 2011, Win Xp
Mission d'une semaine- à plusieurs mois laissez moi un MP...
RP et Midi-pyrénées .Km+++ si possibilité de télétravail
Kudos always accepted / Les petits clicks jaunes sont toujours appréciés
Don't forget to valid a good answer / pensez à valider une réponse correcte
Attachments:
inc_node.vi ‏6 KB

String array into formula node

Hello,
I am taking data from SQL, I am getting multiple rows of data for many different devices. I would like to wire the data into a formula node so I can sepearate and sort via script. However, I am getting an error for "Polymorphic terminal cannot accept this data type". Is there a work around? Can I not wire in a string array to a formula node.
/r
Travo

There are lots of basic string VIs that you can use to parse the string and separate out the individual fields. I would recommend "programming" your application using script nodes. Use the native language. LabVIEW is a fully functional and capable programming language.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

Empty array of unknown size in formula node

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