Permutation based on array indices

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Hi. I want to permute elemnts of a row matrix w.rt to anothe matrix of the same dimension. Below is the part of the code but it gives error.
E3 =[4,73,1,76,109,224,199,134,80,253,156,177,166,167,29,48,206,127,99,234,240,93,102,231,12,65,255,78,79,254,94,239,25,52,31,46,98,235,82,251,72,5,2,75,181,152,43,34,233,100,243,90,182,151,145,188,8,69,3,74,35,42,161,172,221,112,63,14,248,85,115,218,108,225,19,58,66,11,173,160,191,142,144,189,28,49,27,50,241,92,184,149,185,148,129,204,60,17,107,226,211,122,21,56,86,247,6,71,20,57,119,214,33,44,0,77,238,95,96,237,9,68,217,116,201,132,200,133,61,16,170,163,197,136,118,215,59,18,154,179,153,180,114,219,124,209,210,123,126,207,117,216,178,155,23,54,194,139,162,171,157,176,87,246,83,250,7,70,213,120,45,32,249,84,26,51,30,47,135,198,159,174,193,140,64,13,53,24,192,141,55,22,183,150,67,10,212,121,40,37,97,236,81,252,143,190,38,39,164,169,101,232,175,158,110,223,128,205,113,220,203,130,91,242,244,89,138,195,105,228,165,168,125,208,202,131,230,103,106,227,111,222,15,62,137,196,41,36,186,147,229,104,88,245,146,187];
X=[0,241,62,150,100,54,97,104,235,252,5,23,255,135,40,57,232,167,102,222,10,233,78,3,162,24,7,130,118,196,13,39,17,151,238,64,136,215,159,254,37,192,63,163,25,133,14,143,9,216,50,73,123,224,207,98,92,227,112,30,33,174,134,198,121,253,15,147,140,124,90,36,157,113,42,206,127,26,60,103,172,244,94,4,72,218,116,248,188,195,101,168,35,182,107,56,219,138,21,86,110,145,217,66,152,111,228,230,81,76,200,156,183,202,45,52,229,84,209,181,65,125,144,142,18,226,82,11,70,186,179,27,109,88,203,249,80,51,245,193,93,87,68,41,204,132,22,2,170,160,69,210,234,239,180,43,237,197,137,191,67,201,115,61,247,139,47,19,44,164,214,29,16,95,165,240,58,146,6,190,213,28,119,74,75,141,131,96,99,129,71,236,48,108,114,85,251,20,128,153,212,177,250,166,242,32,77,8,155,173,117,205,225,79,49,126,171,89,53,55,158,246,223,189,91,148,59,185,46,105,175,220,208,154,199,1,12,122,243,106,176,31,83,34,38,221,169,194,187,211,178,120,231,149,184,161];
E=X(E3);
Error
Array indices must be positive integers or logical values.
Can any one figure out whats the problem.
Both E3 and X are of class double
  2 Comments
lilly lord
lilly lord on 5 Feb 2021
When I tried to convert values from double to uint 8 i got the same error.
E3_1=uint8(E3);
X_1=uint8(X);
E=X_1(E3_1);
Joseph van 't Hoff
Joseph van 't Hoff on 5 Feb 2021
it is not a problem that E3 consists of doubles, the problem is that E3(115)=0. Therefore you're trying to access the zeroth element of array X, which doesn't exist (Matlab starts indices at 1)
If you do E3(115)=1 and then E=X(E3) it does work (although I assume what you are trying to do is E3a=E3+1 and then E=X(E3a) )

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Accepted Answer

Joseph van 't Hoff
Joseph van 't Hoff on 5 Feb 2021
element 115 of your array E3 is zero, all indices have to be positive integers

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