How to change a numeral of a number?

Hello friends, I want to change the LAST numeral of a number, i.e., I have 543.32145, and I want 543.32140. In fact, I have an array with 200 numbers, but these numbers have the same format than 543.32145, and I want all of them with a zero at the end.

Thank you all =)

[Stephen23]

@Weyller Melo: are these stored as text (e.g char), or numeric (e.g. double)?

Answer 1

[Stephen23]

If you have char vector/array:

>> str = '543.32145';
>> str(end) = '0'
str = 543.32140

If you have numeric values:

>> val = 543.32145
val =            543.32145
>> floor(val*1e4)/1e4
ans =             543.3214

[Weyller Melo]

Thank you, I have numeric values, but I'd like to see the zero (543.32140). Is it possible?

[Stephen23]

"I have numeric values, but I'd like to see the zero (543.32140). Is it possible?"

In general no, because numeric classes do not store any formatting information whatsoever, and most of the format options suppress trailing zeros. But you could write your own fprintf command to do that:

>> val = 543.32145;
>> fprintf('%.5f\n',val)
543.32145
>> fprintf('%.5f\n',floor(val*1e4)/1e4)
543.32140

[James Tursa]

@Weyller: Keep in mind that, in general, decimal fractions like you are using cannot be represented exactly in IEEE double precision arithmetic. E.g.,

>> num2strexact(543.3214)
ans =
    '5.43321400000000039653968997299671173095703125e2'
>> num2strexact(543.32145)
ans =
    '5.433214500000000271029421128332614898681640625e2'

Those are the closest IEEE double precision numbers to the ones you are using. So be careful how you use these downstream, particularly if you are comparing them to other numbers (e.g., for equality).