# 3d graph showing reconstruction error

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guj on 12 May 2011
Question :
I want to plot 3 axis giving me 3d graph ! One axis is error, second is number of iteration, 3rd is % of missing sample
My Conjugate gradient based algorithm is giving me fully reconstructed sample i put in the signal missing samples.
So assuming this is my example
A= signal with missing sample
P=% of missing samples in A
b=reconstructed signal
n=number of iteration
e=error
so i put in signal with 512 samples with 5% missing samples and it takes 20 iteration with say 0.002 as error...
now i will increase the missing part to 10% and it will obviously take more iteration and error may be increase depending on missing samples.
I want to do it from 5% till 70% missing samples...
Looking for your ideas for input
Cheerr
kk

Andrew Newell on 13 May 2011
If I understand your question, you have two input variables, P and n, and a result e = e(P,n). So you create a grid of values for P and n using meshgrid, then calculate e for each pair P(i),n(j). If the resulting error is a smooth function of the inputs, you could plot it using
surf(P,n,e)
or use contour. If it's not so smooth, you might prefer to use imagesc.
EDIT: To clarify, you need a loop something like this:
p = 5:5:70;
n = 20:20:200;
[P,N] = meshgrid(p,n);
e = 0*P; % just an initialization
for i=1:numel(P)
e(i) = simulateAndReturnError(P(i),N(i));
end
surf(P,N,e) % or imagesc(p,n,e)
guj on 15 May 2011
THanks I am able to plot it but stuck with some thing else now ..posted another question in link on using surf and meshgrid

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