topic Re : Re: Re : Different elements in two 1 D array in LabVIEW

Different elements in two 1 D array

Nghtcrwlr — Mon, 15 Dec 2008 23:28:43 GMT

Helloo

I am having two 1 D arrayes. one array consists of r values and other theta values. For example (See attachement) , I want to take the two r values for same theta values and so on fro other tetha valules. how is this possible?

Thanks

Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 00:13:14 GMT

You did not tell us what kid of output you want, but a FOR loop should do what you need. Autoindex on the "angles" and not on the "Rs", and you'll get a 2D array.

Message Edited by altenbach on 12-15-2008 04:13 PM

Re : Different elements in two 1 D array

tinnitus — Tue, 16 Dec 2008 00:14:25 GMT

hello,

thing like that ?

Tinnitus

Re : Re: Different elements in two 1 D array

tinnitus — Tue, 16 Dec 2008 00:16:41 GMT

sorry for collision Master A

Re: Re : Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 00:25:01 GMT

tinnitus wrote:
sorry for collision Master

No problem. As you can see, you have twice as many FOR loops as you actually need, but the idea is the same. 😄

Re: Re : Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 09:57:17 GMT

Hello Tinnitus

Am having Labview version 8.2.. I coudnt open ur VI. But still I used the vi that was posted by altenbach.

anywy thnx for ur help. Is there actually a way to open the higher versions of VI in lower one?

Thnx

Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 10:06:17 GMT

hello Altenbach

Thnx for your help. I was not aware of the indexing stuff.. now it wrks. but still there is some difference in final answer...

for example suppose there is only 1 value of r ; r = 3. and theta = 90,180,270,360

SO complex numbers should be when r=3 and theta =90 (1.5708 rad) ----->0+3i . the Re part of the answers is different in two cases. See attachmenet

I think since it is anyway zero, that difference doesnt affect, right? What could be the reason for that difference in results?

Re: Re : Different elements in two 1 D array

Mathan — Tue, 16 Dec 2008 10:14:50 GMT

Is there actually a way to open the higher versions of VI in lower one?

Its not possible. If you want to do so, just post here. Somebody using that higher version will convert it for your version.

Re : Re: Re : Different elements in two 1 D array

tinnitus — Tue, 16 Dec 2008 10:30:24 GMT

done, i delete the unneeded loop

Tinnitus

Re : Re: Different elements in two 1 D array

tinnitus — Tue, 16 Dec 2008 15:36:44 GMT

it's normal because of approximation of pi and calculation, try to use multiple of pi=3.14xxxxxxxxxxxxxxxxxxx given in numeric palette -> pi constant

also you can modify numeric displaying just for eyes to round values ... (ex 3 digit after coma)

it doesn't affect standard calculation , expect in critical "asservissement" i think (translation not found)

Tinnitus

Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 16:43:19 GMT

Nghtcrwlr wrote:
Thnx for your help. I was not aware of the indexing stuff.. now it wrks. but still there is some difference in final answer...
for example suppose there is only 1 value of r ; r = 3. and theta = 90,180,270,360

SO complex numbers should be when r=3 and theta =90 (1.5708 rad) ----->0+3i . the Re part of the answers is different in two cases. See attachmenet

I think since it is anyway zero, that difference doesnt affect, right? What could be the reason for that difference in results?

Since it is nearly impossible to enter multiples of PI manually wilth full DBL precision, you should maybe do the input in degrees instead and convert to radians in the code.

You should also right-click the indicator and change the display format to something reasonable, e.g. 3 decimal digits as I have done. In automatic formatting (default), you'll get e-format if the values are sufficiently close to zero.

Message Edited by altenbach on 12-16-2008 08:43 AM

Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 17:47:11 GMT

Hello altenbach...

Thankyou very much. I made it already.. changed the figure to 3. now its wrking.

I have another question regarding 2d array.

I am having a 2D array with values. ( see figure) I need to take the first value of the array (index 0,0)for the first time and then elemnt in index (0,1) and then elemnt in index (1,0) and so on ..Lets say i need to do it for many time as the size of array.in figure 6 times...I tried to do it in a for loop. but it gives me only the same value for al the 6 times the loop runs.

Can anyone help?

Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 18:10:24 GMT

Simply reshape your 2D array to a 1D array with a size corresponding to the product of the sizes.

Then autoindex on a FOR loop and you'll get the elements in the desired order, one per iteration intil you run out of elements. 😄

Message Edited by altenbach on 12-16-2008 10:10 AM

Re : Re: Different elements in two 1 D array

tinnitus — Tue, 16 Dec 2008 18:16:13 GMT

hello Nghtcrwlr,

tell me if i stink feet,

definetifly , i'am too slow...

Message Edité par tinnitus le 12-16-2008 12:15 PM

Message Edité par tinnitus le 12-16-2008 12:16 PM

Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 21:08:48 GMT

Hello altenbach...

That way it worked. Thanx..

Now am getting 4 1d arrays. Now i need the first values of all those arrays together, second elements of all those arrays together and so on till the number of arrays. I tried to put an index array in a for loop. but didnt work. Any hints?

Re: Re : Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 21:10:38 GMT

Hi tinnitus

Thnx for the help...actually i wanted the values in a sequence but not in time intervals.

Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 21:23:45 GMT

Nghtcrwlr wrote:
Now am getting 4 1d arrays. Now i need the first values of all those arrays together, second elements of all those arrays together and so on till the number of arrays. I tried to put an index array in a for loop. but didnt work. Any hints?

Autoindex all four arrays into the same FOR loop.

If it does not work, show us your code so we can see what the problems is.

Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 21:44:47 GMT

Hello ALtenbach

I have attached the code. and also what is to be done is mentiond. Now i need to take the values of first column of this array and take each elements and perform some calculations. and so on for the next columns the same.... Please help me!

Thnx

Message Edited by Nghtcrwlr on 12-16-2008 03:44 PM

Re: Different elements in two 1 D array

altenbach — Tue, 16 Dec 2008 22:16:36 GMT

You really should do a few tutorials first. Simplify!!!

Your FOR loop is not needed at all.
The rouding operations need to be done only once, and not multiple times. You can branch the wire later.
Youre not really tellin us what kind of "processing" you want to do, but if you transpose the 2D array, you'll process an original column at a time using autoidenxing. Inside the loop you can you a second FOR loop or an "index array" node (resized to four outputs) to get to the elements.

Here's a quick draft on how it could look like.

Message Edited by altenbach on 12-16-2008 02:16 PM

Re: Different elements in two 1 D array

Nghtcrwlr — Tue, 16 Dec 2008 22:44:07 GMT

Hello Altenbach

I have modified the vi as u mentioned. The "processing" which i mentione dis as below: the output of the for loop ( as in the attachmenet u posted "Process columns PNG") is a two 2D arrays. One array containing the real part and the other imaginary part. Both arrays are shown in attahment.Now i want to take the values of array 1> column 1 >element 1 and array 2>colum 1>elemnt 1 i.e as shown in attahment [(0,2).(1,2) (1,1),(0,1)] ... Second colum of both arrays (1,3)(2,3)(2,2)(1,2).. and so on.. these values together make an index number for an array. I want to use these index numbers to exract ements from an array.

Hope you understood the problem.

Message Edited by Nghtcrwlr on 12-16-2008 04:44 PM