MATLAB: How can i use the ceil function rightly

question 1

i notice that the ceil function does not work right on some value and i do not know why
for example:i used ceil(2.7/0.3) and it results 10 but the right result must be 9
However,when i tried another value,e.g ceil(2.4/0.3),it results 8 which is right
this function also work wrong on some another values,like ceil(2.1/0.3),ceil (4.2/0.3)
Thank you

Best Answer

>> 2.7/0.3 - 9
ans =
1.77635683940025e-15
so ceil() is correct.
As to why 2.7/0.3 is not exactly 9, see http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F
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