how to filter out decimals

function s = Fnkt(n)

syms k x

s = symsum(k,k,0,n);

if s<=0

s = 0;

end

Can somebody help me figure out, how do i filter out decimals ?

Example:

Fnkt(2) , then i will get 1+2=3

for negative numbers i want to get 0 .

But how do i get rid of decimals, for example Fnkt (2.5) or neg. decimals (-2.5) to get also a zero ?

Answer 1

[Jan]

function s = Fnkt(n)
if n <= 0 || n ~= floor(n)
   s = 0;   
   return; 
end
syms k x
s = symsum(k,k,0,n);
end

Do you realy want to calculate this symbolically? What about:

function s = Fnkt(n)
if n <= 0 || n ~= floor(n)
   s = 0;   
else  % sum(1:n) with Gauss' method:
   s = n * (n + 1) / 2;
end
end

[Osman Ballhysa]

thank you , oohhh i see. it could also work with round(n) instead of floor(n)

[Osman Ballhysa]

yeah i was just messing around and trying, symsum was probabily not the smartest way to do it