topic Re: Create array with for loop in LabVIEW

Create array with for loop

Egorkkk — Sun, 17 Feb 2013 17:23:10 GMT

Hello.

Stupid question, but i can't do it myself.

I receive scalar byte data from com port in main while loop and want to make 1D array with adjustable size for further filtering and so on. Simple "for loop" with indexed output makes me array with all the same elements.

Can anyone tells me how can i make this?

Thank you.

Re: Create array with for loop

Dennis_Knutson — Sun, 17 Feb 2013 17:55:45 GMT

Build array with a shift register. This would be in your main acquisition loop. It does sound like you could make use of the pt-by-pt functions, though.

Re: Create array with for loop

Egorkkk — Sun, 17 Feb 2013 18:01:32 GMT

Can i tell more about you solution? Shift registers in main loop or in for loop? Or can you show me example, please

Re: Create array with for loop

Dennis_Knutson — Sun, 17 Feb 2013 18:12:33 GMT

In the main loop where you are doing the scalar acquisition. You need to post your VI if you need help.

Re: Create array with for loop

Egorkkk — Sun, 17 Feb 2013 20:00:49 GMT

Ok, thank you very much. I'll try this and post if there will be questions. Thank you.

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 06:33:01 GMT

Why can't you use string to byte array function.

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 10:04:42 GMT

First, sorry for my english.

I receive bytes every 10ms and want to use filters and other processing. So, thats why i want to create 1D array with adjustable size. In other words, "stacking" 8 (or 4 or 100) bytes to 1D array. I know, that this is simple, but have a "wall" in my head )

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 10:20:24 GMT

Try this & let me know.

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 10:41:03 GMT

Ok, i was try your example. I'm replace random generatro with input from visa and see that all elements of array are identical...

Here is my VI. First part of it is simply for formatt input from COM port - take two bytes from array and make word.

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 10:43:12 GMT

2011 compatible VI please

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 10:44:21 GMT

Suppose each time from the serial port 25 byte you read then use one string to byte array & thats it.

It has to work.

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 10:44:34 GMT

Sorry, take it

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 10:47:12 GMT

>>Suppose each time from the serial port 25 byte you read then use one string to byte array & thats it.

No, there are many other information in com port input. I'm take two bytes from port, make word and only after this i can work with it

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 10:54:32 GMT

Then whats a problem, Read required byte using array subset as you already doing. What more you are looking for ?

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 10:55:37 GMT

Can you give me example, please?

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 10:57:56 GMT

Tell me first ?

If the serial data is 25 bytes what operation you want to perform on that, I will post the example but first let me know the requirement ?

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 11:06:35 GMT

Ok.

I have info from gyros and accelerometers position sended in blocks by UART. 1st byte - LSB axis X, 2nd byte - MSB axis X, 3rd byte - LSB axis Y and so on.

All of this data will be processed in many different ways.

In my question i only want to now, how can i make array from periodic scalar data. All of the examples use random numbers generator INSIDE for loop, but i can't. My data comes from outside. When i connect it directly to "for loop" my array fills with same elements. For example, i have "254" on input of the for loop, and take 1D array with size of forloop count and all elements are "254". That is my problem )

Thank you

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 11:16:47 GMT

How are you reading data i.e. in each serial read how many bytes you are receving. If you are reading multiple times then you need to read inside for loop only ? Which data you want to make array

Let me know this.

Re: Create array with for loop

Ranjeet_Singh — Mon, 18 Feb 2013 11:18:23 GMT

See my last post in which i attached VI. Instead of random number you can use your serial read VISA function.

Re: Create array with for loop

Egorkkk — Mon, 18 Feb 2013 11:22:27 GMT

Now, with only one gyro, in each while loop i'm receive 6 bytes. 2 bytes - X, 2 bytes - Y, 2 bytes - Z.

I want to work with only one axis - X. I do not want to use PtbyPt filters, so i must have 1d array of U16 for filtering. Because this is experimental project, i want to manually adjust array size. Only thing that i need is make 1D array from scalar data.