matlab/scilab HELP!!!

If anyone knows matlab or scilab i would like input.

Im trying to graph x^2, x^3 and so on up to x^9, on a X range from 0-4. I can create the graph just fine, but when i have to switch it to semilogY i get an error. It say's i can only have positive y-values to switch to logY an im not to sure what to do.

this is the code so far, and for the adjustment for the x range i do that manually instead of by code, thats why its not present.

-->x = 0:1:4;

-->y = x^2;

-->plot(y)

-->y = x .^2;

-->plot(y)


any if you know the error codes, this is what i got...

Error: data_bounds on y axis must be strictly positive to switch to logarithmic mode.
at line 4 of function generic_i_h called by :
at line 2 of function %c_i_h called by :
at line 4 of function LogtoggleY called by :
LogtoggleY('l')
while executing a callback

 

ttt

 

btt

 

whats the period for?

 

in the y = x .^2 ?

if so thats telling it to do it for every intereger. Saves from writing more then have to.