Asking about an output

%% Differentiation of tan^{-1}x at 1
clear all;
clc;
f=@(x) atan(x);
a=1;
h=10.^[-2:-1:-4];
eVal=1/(1+a^2);
%% Forward difference formula
errf=zeros(length(h),1);
for i=1:length(h)
    fDiff(i)=(f(a+h(i))-f(a))/h(i);
    errf(i)=abs(eVal-fDiff(i));
end
disp(errf);
%% Central difference formula
errc=zeros(length(h),1);
for i=1:length(h)
    fCen(i)=(f(a+h(i))-f(a-h(i)))/(2*h(i));
    errc(i)=abs(eVal-fCen(i));
end
disp(errc);
%% Backward Difference formula
errb=zeros(length(h),1);
for i=1:length(h)
    fBack(i)=(f(a)-f(a-h(i)))/h(i);
    errb(i)=abs(eVal-fBack(i));
end    
disp(errb);

The output is:
   0.002491666914583
   0.000249916666750
   0.000024999166126

   1.0e-05 *

   0.833308332937044
   0.008333328516130
   0.000083316731292

   0.002508333081242
   0.000250083333320
   0.000025000832460
   
   My question is why the term 1.0e-05 * appearing?

Answer 1

[Stephen23]

"My question is why the term 1.0e-05 * appearing?"

Because you are displaying the values in the command window using long format. Change the format if you want to display the numbers using another format, e.g.:

>> format long
>> errc
errc =
   1.0e-05 *
   0.833308332937044
   0.008333328516130
   0.000083316731292
>> format long G
>> errc
errc =
      8.33308332937044e-06
      8.33332851613022e-08
      8.33167312919159e-10
>> format short
>> errc
errc =
   1.0e-05 *
    0.8333
    0.0083
    0.0001
 

etc. If you want more format control than those offer then use fprintf.