how to check negative values are there or not in a matrix????

i have a matrix a=[0.2 0.1 -0.1 0 0.9], now i want to check whether there is any negative value if yes then those element i want to make zero.

plz plz help me....

a<0 makes all greater than as 1 and other 0. but i want to make only negative values zero and other as same as they are.

[Asif Newaz]

u can use the 'sign' function.

[Dyuman Joshi]

An approach to show off (lol) -

a=[0.2 0.1 -0.1 0 0.9]

a = 1×5

0.2000 0.1000 -0.1000 0 0.9000

max(a, 0)

ans = 1×5

0.2000 0.1000 0 0 0.9000

Answer 1

[Mischa Kim]

suchismita, use

 a(a<0) = 0;

[suchismita]

thank you so much....

[juveria fatima]

@ misha kim after making the negative integer to zero in matrix i want to get back to the a as originally with negative integers ,how do i do it?

[KEYUR BORAD]

Thanks @Mischa Kim this syntax helped me to find if a vector contains both neg and pos value or not!!

Answer 2

[Thomas Richner]

If you want to know if a matrix contains any negatives (but not to replace them) the use

contains_negative = any(a<0); % returns true or false

Answer 3

[Anirban Naskar]

Hi Suchismita,

You can use something like the following:

[m n]=size(a);
for i=1:m
    for j=1:n
        if a(i,j)<0
        disp('contains negative element');
        a(i,j)=0;
        end
    end
end

[suchismita]

thank u so much.... :)

[juveria fatima]

@ Anirban nasker you are converting the negative number in matrix to positive perfectly fine

but in my case i have i have to first convert negative to postive and again i have to get back to original 'a matrix' can any help in writing the reverse function for it