Comparing strings with extra zero

Hello, I am wanting to perform a safety check that 2 strings are the same:

send: 297.043       rec: 297.043
send: 298.030       rec: 298.03
send: 300.833       rec: 300.833

Theres a problem when I try to test for string equivalence i.e. the 298.030 value, not sure how to resolve this.

thanks

Answer 1

[Saurabh]

Hi @Jason,

When comparing strings for equivalence, even a small difference in formatting (such as trailing zeros) can cause them to be considered different. In this case, the issue arises with the second pair of strings, where one has a trailing zero and the other does not ("298.030" vs. "298.03").

To perform a safety check that considers such cases, consider converting the strings to numerical values before comparing them. This approach ignores formatting differences like trailing zeros.

Use 'str2double' to convert the string representations of numbers to actual numerical values.

Leverage the following link to know more about function:

https://www.mathworks.com/help/matlab/ref/str2double.html

I hope this helps.

[Jason]

Thanks, I did actually do that.

So my raw values are actually these:

send =

2.970429350000000e+02


rec =

'   297.043 '


dE =

6.500000000642103e-05

send
send
dE= abs(send-str2double(rec))      
if dE<=0.00001
    do something
end

[Jason]

Seems I have to do this:

send=str2double(sprintf('%0.3f',send))

[Saurabh]

Thanks for the reply,

If 0.00001 is too strict for the application, consider increasing the tolerance to accommodate the precision differences. For example, consider using 0.0001 instead?