Editing FAQ
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=General= | =General= | ||
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* Permission errors | * Permission errors | ||
** '''Solution 1:''' Octave | ** '''Solution 1:''' Octave on MS Windows uses VBS scripts to start the program. You can test whether your system is blocking VBS scripts by doing the following: | ||
**# Using Notepad or another text editor, create a text file containing only the text: <pre>msgbox("This is a test script, Click OK to close")</pre> | **# Using Notepad or another text editor, create a text file containing only the text: <pre>msgbox("This is a test script, Click OK to close")</pre> | ||
**# Save the file on your Desktop with the name {{Path|testscript.vbs}} (be sure that the editor didn't end it in .txt or .vbs.txt). | **# Save the file on your Desktop with the name {{Path|testscript.vbs}} (be sure that the editor didn't end it in .txt or .vbs.txt). | ||
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** '''Solution 3:''' Did you install Octave on a network-drive? Do you have the execution permissions? | ** '''Solution 3:''' Did you install Octave on a network-drive? Do you have the execution permissions? | ||
** '''Solution 4:''' Is your computer managed by your company? Does your administrator prohibit script execution? | ** '''Solution 4:''' Is your computer managed by your company? Does your administrator prohibit script execution? | ||
==I do not see any output of my script until it has finished?== | ==I do not see any output of my script until it has finished?== | ||
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==Why is Octave's floating-point computation wrong?== | ==Why is Octave's floating-point computation wrong?== | ||
Floating-point arithmetic is an approximation '''in binary''' to arithmetic on real or complex numbers. Just like you cannot represent 1/3 exactly in decimal arithmetic (0.333333... is only a rough approximation to 1/3 | Floating-point arithmetic is an approximation '''in binary''' to arithmetic on real or complex numbers. Just like you cannot represent 1/3 exactly in decimal arithmetic (0.333333... is only a rough approximation to 1/3), you cannot represent some fractions like <math>1/10</math> exactly in base 2. In binary, the representation to one tenth is <math>0.0\overline{0011}_b</math> where the bar indicates that it repeats infinitely (like how <math>1/6 = 0.1\overline{6}_d</math> in decimal). Because this infinite repetition cannot be represented exactly with a finite number of digits, rounding errors occur for values that appear to be exact in decimal but are in fact approximations in binary, such as for example how 0.3 - 0.2 - 0.1 is not equal to zero. | ||
In addition, some advanced operations are computed by approximation and there is no guarantee for them to be accurate, see [https://en.wikipedia.org/wiki/Rounding#Table-maker.27s_dilemma Table-maker's dilemma] for further references. Their results are system-dependent. | In addition, some advanced operations are computed by approximation and there is no guarantee for them to be accurate, see [https://en.wikipedia.org/wiki/Rounding#Table-maker.27s_dilemma Table-maker's dilemma] for further references. Their results are system-dependent. |