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[debugging] several changes

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Jan Grewe 2017-10-21 16:21:25 +02:00
parent bd446b8c0c
commit 3aae7a94d9
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debugging/lecture/debugging.tex
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@ -96,27 +96,27 @@ ans =
65 % wtf ?!?
\end{lstlisting}
The first two indexing attempts in listing \ref{indexerror_listing}
are rather clear. We are trying to access elements with indices that
are invalid. Remember, indices in \matlab{} start with 1. Negative
numbers and zero are not permitted. In the third attemp we index
using a floating point number. This fails because indices have to be
'integer' values. Using a character as an index (fourth attempt)
leads to a different error message that says that the index exceeds
the matrix dimensions. This indicates that we are trying to read data
behind the length of our variable \codevar{my\_array} which has 100
elements.
The first two indexing attempts in listing \ref{indexerror} are rather
clear. We are trying to access elements with indices that are
invalid. Remember, indices in \matlab{} start with 1. Negative numbers
and zero are not permitted. In the third attemp we index using a
floating point number. This fails because indices have to be 'integer'
values. Using a character as an index (fourth attempt) leads to a
different error message that says that the index exceeds the matrix
dimensions. This indicates that we are trying to read data behind the
length of our variable \codevar{my\_array} which has 100 elements.
One could have expected that the character is an invalid index, but
apparently it is valid but simply too large. The fith attempt
finally succeeds. But why? \matlab{} implicitely converts the
\codeterm{char} to a number and uses this number to address the
element in \varcode{my\_array}.
apparently it is valid but simply too large. The fith attempt finally
succeeds. But why? \matlab{} implicitely converts the \codeterm{char}
to a number and uses this number to address the element in
\varcode{my\_array}. The \codeterm{char} has the ASCII code 65 and
thus the 65th element of \varcode{my_array} is returned.
\subsection{\codeterm{Assignment error}}
This error occurs when we want to write data into a vector.
\paragraph{Name error:}
\paragraph{Arithmetic error:}
\subsection{Name error}
\subsection{Arithmetic error}
\section{Logical error}
Sometimes a program runs smoothly and terminates without any