manipulation of seperate vector values

so i have a vector set of values and wanted to round all the values to the nearest positive, even integer. and all the values less then zero are rounded to zero. any idea on how to do this using an mfile?

Answer 1

[Jan]

v(v<0) = 0;
v = round(v/2) * 2;

Answer 2

[Paulo Silva]

%v is your vector
idx=v<0; %get the index of all values lower than 0
idx1=v>0; %get the index of all values higher than 0
v(idx)=0; %substitute the lower than 0 values by 0
v(idx1)=round(v(idx1)) %substitute higher than 0 values by nearest positive

In case you want a special form of the round function that does nearest positive and even integer get the round2even function or round2

[Jan]

Or shorter: v = round(v); v(v<0)=0;

[Paulo Silva]

That's shorter but does unnecessary rounding of the negative values

[Jan]

Correct. Therefore your method will be faster, if a lot of negative numbers occur.

Answer 3

[Yusuf]

yes thanks that works but i need it to round to the nearest even integer?

[Jan]

Ah, now I understand the "even integer" in your question.