Problem with 'subs' function

Hi all,

I'm having a strange problem with the 'subs' function. Basically, func_A_test and func_j_test are symbolic functions of p_M. I want to evaluate them over a vector of p_M values from 0.005 to 0.007. When I substitute in 0.005 for p_M I get a different value than if I substitute the first value of the p_M vector (p_M_vec) which is also 0.005.

>> p_M_vec = [0.005:0.0005:0.007]

p_M_vec =

    0.0050    0.0055    0.0060    0.0065    0.0070

>> subs(func_A_test,{p_M},{p_M_vec(1)})

ans =

486.1358

>> p_M_vec(1)

ans =

    0.0050

>> subs(func_A_test,{p_M},{p_M_vec(1)})

ans =

486.1358

>> subs(func_j_test,{p_M},{p_M_vec(1)})

ans =

   14.1930

>> subs(func_A_test,{p_M},{0.05})

ans =

   48.3781

>> subs(func_j_test,{p_M},{0.05})

ans =

   12.5569

Not sure why this is happening. Any help is greatly appreciated. I am very confused about this.

Thanks so much.

Regards, Rama

Answer 1

[Walter Roberson]

I do not see the problem in what you show.

Each time you substitute 0.005 (from whatever source) in to funcs_A_test, you get 486.1358 . When you substitute 0.05 instead to funcs_A_test, you get 48.3781 .

When you substitute 0.005 in to func_j_test, you get 14.1930. When you substitute 0.05 instead to funcs_j_test, you get 12.5569.

Perhaps you misread between 0.005 and 0.05 ?