Even More Matrix Computations

Even More Matrix Computations - Messages

#1 Posted: 12/5/2021 9:52:56 AM
ianlh

ianlh

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Hi,

Back again with another matrix problem, this time on interpolation and bilinear interpolation.

Below is the matrix and relevant values to use (d.t and d.dd) to find the values in sigma.ct matrix

matrix1.JPG

There is a condition that any value in d.dd that is below vy=20 shall use the value in the first row, and not be interpolated below. e.g. d.t = 500 & d.dd = 2.6637 sigma.ct shall be 58.

I have used the linterp2 function to find the values which meet this criteria, which works on its own, but I cant get it to work in a if condition. I have used the interpBilinear function to get the values when d.dd is above vy=20 and this works within the if loop as it gives only the last two rows of the above requirements.

When combined in the for loop the below happens, the linterp2 still gives all the rows, rather than only giving the first 7 (in this case), but gives the correct number of columns.

Is there any way of correcting this? As a thought do I need to put the condition check d.dd<20 within the linterp2 function. if so where would I put it?

matrix2.JPG

Bilinear Interpolation2.sm (24 KiB) downloaded 33 time(s).

Thanks in advance
Ian
#2 Posted: 12/5/2021 2:23:09 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

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Wrote

Back again with another matrix problem, this time on interpolation and bilinear interpolation.


Sorry, I don't understand the problem.

Bilinear Interpolation2.sm (24 KiB) downloaded 30 time(s).


#3 Posted: 12/5/2021 4:35:21 PM
ianlh

ianlh

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Wrote

Wrote

Back again with another matrix problem, this time on interpolation and bilinear interpolation.


Sorry, I don't understand the problem.

Bilinear Interpolation2.sm (24 KiB) downloaded 30 time(s).




Hi,

the result should look like:

matrix3.JPG

#4 Posted: 12/5/2021 6:47:57 PM
Jean Giraud

Jean Giraud

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Wrote

the result should look like:


... finish the construction.

stack.PNG
#5 Posted: 12/5/2021 7:04:41 PM
overlord

overlord

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Group: Moderator

Since your linterp2() function creates arrays,
an index is needed at q inside for_loop calculation.

Regards

2021-12-06_01-02.png
#6 Posted: 12/6/2021 5:36:14 AM
ianlh

ianlh

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Once again so close, thanks for the pointer

Below is corrected:
Bilinear Interpolation2 v1.sm (22 KiB) downloaded 26 time(s).

Thanks
Ian
#7 Posted: 12/6/2021 8:59:52 AM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

You can recast the bilinear in preparation to CreateMesh

Bilinear Interpolation2 v1.sm (43 KiB) downloaded 29 time(s).
#8 Posted: 12/6/2021 10:12:33 AM
ianlh

ianlh

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Nice, thank you Jean
#9 Posted: 12/6/2021 12:44:00 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Wrote

You can recast the bilinear in preparation to CreateMesh


... it didn't attach ???

Bilinear Interpolation2 v1 Next.sm (71 KiB) downloaded 35 time(s).
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