plot the relationship between function and specific variable

Want to see the plot between t and thada. In this script is not showing, what is going wrong? please help

a=0.2;
b=0.3;
for thada= 0.1:1:20
t=[1+(((thada^a)-1)*((thada^b)-1))/(thada-1)];
tf= log(t)/log(thada)
plot(thada,tf);
end

Answer 1

[Adam]

a=0.2;
b=0.3;

thada= 0.1:1:20
tf = zeros( size( theta ) );

for n = 1:numel( thada )
   t=[1+(((thada( n )^a)-1)*((thada( n )^b)-1))/(thada( n )-1)];
   tf( n ) = log(t)/log(thada( n ))
end

plot(thada,tf);

should work, but I only edited off the top of my head so there may be errors.

[Najiya Omar]

it works perfectly thank you very much