Multiply values in array by *-1

Hi,

I have an array 1X106. I want to be able to multiply specific entries in the array by -1.

e.g., multiplying the 16, 17 and 18 value in the array by -1 whilst still keeping the remainder of the array with the original values.

Any help would be greatly appreciated,

Thanks!

Answer 1

[Chunru]

a = randn(1, 106);
a(14:20)

ans = 1×7

0.8401 1.6024 1.0470 -1.1157 0.2066 -2.0192 -0.6220

a(16:18)=-a(16:18);
a(14:20)

ans = 1×7

0.8401 1.6024 -1.0470 1.1157 -0.2066 -2.0192 -0.6220

[Edward Keavney]

Perfect, thank you very much!