Difference between revisions of "Mid"

Revision as of 00:45, 25 March 2016

Mid(x)

Evaluates «x» in Mid-Mode.

Whenever an expression or subexpression is evaluated, it is evaluated either in Mid-mode or Sample-mode, in which sample-mode carries through information about uncertainty whereas mid-mode does not. The article on Evaluation Modes explains this in detail. Mid(x) forces the evaluation of «x» to occur in Mid-mode even when the current evaluation mode is sample-mode.

The Sample(x) function does the opposite -- forcing «x» to be evaluated in sample mode.

Distribution functions return their median value in Mid-mode, or a Monte Carlo when evaluated in Sample-mode.

Mid(x) is also used as an meta-expression in a MultiTable to show the computed value of «x».

Examples

Suppose x := Uniform(1,1)^2

Mid(x) → 0

Median(x) → 0.25

Mean(x) → 0.3333

When Mid is evaluated, the median value of Uniform(-1,1) is used, which is 0 and is then squared to get the mid-value of x. As seen, this is not equivalent to the median of «x» when uncertainty is properly accounted for.

@@ Line 19: / Line 19: @@
 :<code>[[Median]](x) &rarr; 0.25</code>
 :<code>[[Mean]](x) &rarr; 0.3333</code>
-When [[Mid]] is evaluated, the median value of <code>Uniform(-1,1)</code> is used, which is 0. As seen, this is not equivalent to the median of «x» when uncertainty is properly accounted for.
+When [[Mid]] is evaluated, the median value of <code>Uniform(-1,1)</code> is used, which is 0 and is then squared to get the mid-value of x. As seen, this is not equivalent to the median of «x» when uncertainty is properly accounted for.
 == See Also ==