How to convert cell array into numerical array correctly with precision(no roundup value)?

Hello,

I need to convert cell array into numerical array correctly with precision(no roundup value). I have tried various ways to get it right but couldn't. Any help is much appreciated.

Input:

L = {'38.95676800902' '38.95676807489' '38.95676821300' '38.95676838920' '38.95676853021'}

Desired output:

L_out= [38.95676800902 38.95676807489 38.95676821300 38.95676838920 38.95676853021]

*I used three methods but I am not getting it right,

1: Using cell2mat %This shows the output I got in Char instead of double(number), I am collecting output using counter in this case as it shows only one value instead of array when used this function.

L_out =

33333

88888

.....

99999

55555

66666

77777

66666

88888

00235

07183

94390

08022

29001

2: Using printf and scanf

S = sprintf('%s ', L{:}); L_out = double(sscanf(S, '%f'));

L_out = [38.9567 38.9567 38.9567 38.9567 38.9567]

This one is not accurate at all for my purpose

3. Using str2double

L_out = [38.9567 38.9567 38.9567 38.9567 38.9567]

In this way again I am not getting it accurate.

Is there a way to get it right?

Answer 1

[Guillaume]

The correct and fastest way to convert a cell array of strings into a matrix of number is indeed with str2double

>>L = {'38.95676800902' '38.95676807489' '38.95676821300' '38.95676838920' '38.95676853021'}

>>L_out = str2double(L)
L_out =
  38.95676800902  38.95676807489  38.956768213  38.9567683892  38.95676853021

This will convert the strings to the nearest number representable by a double (some numbers such as 0.1 can't be represented exactly as double).

In this way again I am not getting it accurate.

Yes, you are. The format matlab uses to display numbers has no bearing on the actual value stored in the number. Change the display format with format and you'll see the number are as accurate as can be.

>>format short g;
>>L_out
L_out =
     38.957       38.957       38.957       38.957       38.957
>>format long g
>> L_out
L_out =
  38.95676800902  38.95676807489  38.956768213  38.9567683892  38.95676853021

[Shree]

Hello, Thank you for your reply.

You are right. I am getting the actual value when displayed with long format but in the matlab workspace why it still shows the shorter format? Is there any way to see these values in matlab workspace instead of displaying?