1-D interpolation question

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Keny 2014-4-21

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评论： Walter Roberson 2014-4-21

i have some point and values matrix. [100 ..., 195 ....,300 ...]; and i have another matrix that goes from 50 to 400; if i use interp1 and extrap option, my extrap values are added in the beginning and end of the result.

but i want to put 2 different values in beginning and end.

how can i do that?

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Answer 1

Walter Roberson 2014-4-21

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Turn off extrap. Let NaN be filled in. Then use find() and isnan() to find the boundaries of the extrapolation, and write the extrapolation constants in as desired.

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Keny 2014-4-21

if i do that there are some nan values both side. for example i want to put a value "50" in the beginning and "100" in the end. how can i seperate the NaN values in the matrix then put my values?

Walter Roberson 2014-4-21

在 MATLAB Online 中打开

idx = ~isnan(YourVector);
first_boundary = find(idx, 1, 'first');
YourVector(1:first_boundary - 1) = 50;
second_boundary = find(idx, 1, 'last');
YourVector(second_boundary + 1 : end) = 100;