topic Re: MATHSCRIPT in LabView 7.1 in LabVIEW

MATHSCRIPT in LabView 7.1

winter888 — Fri, 15 Mar 2013 02:31:34 GMT

Hello,

How can I use MATHSCRIPT in LabView 7.1 ?

thank you

Re: MATHSCRIPT in LabView 7.1

Ray.R — Fri, 15 Mar 2013 02:46:49 GMT

I don't think it existed with LabVIEW 7.1..

I will have to check... But if I rely on my memory, I think it came out with LabVIEW 8.0.

Re: MATHSCRIPT in LabView 7.1

tst — Fri, 15 Mar 2013 03:30:27 GMT

Ray is correct that LV 8.0 is the first version that supported Mathscript. I believe ealier versions had the Matlab node, so if you have Matlab, you might be able to convert your code to it. I'm not sure how similar the languages are.

Re: MATHSCRIPT in LabView 7.1

winter888 — Fri, 15 Mar 2013 10:22:26 GMT

Thnk you.

Can anyone please help me to convert this MatLab code into LabView ...!

stop = 0.001;
start = -0.001;
point = 10;
distance = ( stop - start ) / point;
t = ( start : distance : stop );
t1 = t(find(t~=stop))

t1 will give me array of 10 points.

thank you.

Re: MATHSCRIPT in LabView 7.1

tst — Fri, 15 Mar 2013 12:07:30 GMT

I have no idea what the find function does, but if the point is to generate an array of N points from A to B then you can just call the Ramp Pattern VI (search for it in the palette) and if you don't have it, just use a for loop with A+((A-B)/N*i).

Re: MATHSCRIPT in LabView 7.1

Ray.R — Fri, 15 Mar 2013 13:43:04 GMT

@winter888 wrote:

Thnk you.

Can anyone please help me to convert this MatLab code into LabView ...!

stop = 0.001;
start = -0.001;
point = 10;
distance = ( stop - start ) / point;
t = ( start : distance : stop );
t1 = t(find(t~=stop))

t1 will give me array of 10 points.

thank you.

Is the code below what you are looking for?

I looked up the last function... Did you want the indices for all values which are not equal to 0.001???

pretend that -5.4E-20 is zero..

Re: MATHSCRIPT in LabView 7.1

winter888 — Sat, 16 Mar 2013 00:32:06 GMT

Thanks Ray,

Nice code. Is there any way I can make that wired long digit number to zero in my array?

And as there should be 10 points, it would be nice if I can delete the last number, which is equal to 'stop'.

And that's what I did in my mathscript with 't1'.

Re: MATHSCRIPT in LabView 7.1

johnsold — Sat, 16 Mar 2013 00:37:28 GMT

Use Array Subset.

Lynn

Re: MATHSCRIPT in LabView 7.1

Ray.R — Sat, 16 Mar 2013 14:41:53 GMT

There are a few ways of doing this. The approach similar to: t1 = t(find(t~=stop)) is not recommended because searching a double or ext precision may not provide a match. The reason I initially asked about the function is because you mentionned that it returned an array of 10 elements, whereas it really returns 9.

Unfortunately, the method shown below is not flexible as it will only remove the last value, which should always be the stop value in this exercise.. You can use Array subset (preferred as Lynn mentionned) or delete from array. There are other tricks, but I think these 2 are the more efficient ones.

Re: MATHSCRIPT in LabView 7.1

tst — Sat, 16 Mar 2013 17:06:06 GMT

Like I said before, using the Ramp Pattern VI would be simplest, but you could also do it with the for loop, which will produce simpler code and where you won't need to cut the array, but it will have exactly the right number of points to begin with.

As for the long number, the method I suggested might or might not return it as a proper zero (that depends on the way floating point calculations work), but you can at least display it as zero by right clicking the numeric control inside the array, going into the display format page and changing the display format to display fewer digits of precision.

To learn more about LabVIEW, I suggest you try looking at some of these tutorials.

Re: MATHSCRIPT in LabView 7.1

Ray.R — Sat, 16 Mar 2013 18:46:06 GMT

tst is right.

Using the Ramp function is much easier. Same issues with the use of doubles..

I was too focused on reproducing the Matlab code that I lost sight of the basic function that it represented.

The Ramp function in LabVIEW is similar to:

linspace(start, stop, points)

There is an interesting variation of the results with each method.

Re: MATHSCRIPT in LabView 7.1

winter888 — Mon, 18 Mar 2013 00:23:07 GMT

Hi Ray,

Thanks a lot for your help. I have solve it. I got 10 points for 't1' and 11 points for 't' . Its exactly as the mathscript.

thanks all of you.

Re: MATHSCRIPT in LabView 7.1

winter888 — Mon, 18 Mar 2013 00:37:20 GMT

Hi Ray,

Ramp is a great function. Thanks a lot.

Re: MATHSCRIPT in LabView 7.1

RavensFan — Mon, 18 Mar 2013 00:45:43 GMT

Then you should mark Ray's message as the solution to your question rather than your own thank you message. First you will have to go to the options menu to the upper right of your message to unmark it as the solution.

Re: MATHSCRIPT in LabView 7.1

winter888 — Mon, 18 Mar 2013 01:10:04 GMT

Hi Ravens,

Sorry for that. I didn't mean to insult Ray. I appriciate the help. But there is a bit difference between Ray's and mine code. I changed a bit, and it is the exactly what mathscripts 't' and 't1' dose. Please see my attached file.

Thanks.

Re: MATHSCRIPT in LabView 7.1

RavensFan — Mon, 18 Mar 2013 02:43:34 GMT

Really? What you have looks pretty much like what Ray gave you in message #9. So he gave you 99% of the answer, and your one tweak of the way to derive the final array is the solution?