Programmer Guide/SPU Reference/SELECTAB: Difference between revisions

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|<var>Y</var>[i] = max(<var>A</var>[i],<var>B</var>[i])
|<var>Y</var>[i] = max(<var>A</var>[i],<var>B</var>[i])
|}
|}
with: 0 &le; i &lt; length of <var>A<sub>vector</sub><var>
with: 0 &le; i &lt; length of <var>A<sub>vector</sub></var>
 
 
 
The averaging algorithm is defined by the inputs <var>TYP</var> and <var>T</var>. The atom averages the elements <var>X</var>[''i'',''j'']<sub>''t''</sub> over evaluation cycles t (''i''=row index, ''j''=column index, ''t''=cycle counter) and stores the averaged value in the element <var>Y</var>[''i'',''j'']<sub>''t''</sub>.
 
The cycle counter ''t'' is initialized with 0 and incremented by 1 after each evaluation cycle. The cycle counter is reset, if the input <var>RS</var> is set to a value greater than <code>0</code>. The input <var>RS</var> is checked each time the SPU is started.
:;infinite average:
::<var>TYP</var>=<code>0</code> or <code>linear</code>
::<var>T</var>=<code>0</code>
::<math>Y[i,j]_t =
\begin{cases}
X[i,j]_t & \mbox{if }t=0 \\
\frac{1}{t+1}(t.Y[i,j]_{t-1}+X[i,j]_t) & \mbox{if }t>0
\end{cases}
</math>
:;running average:
::<var>TYP</var>=<code>0</code> or <code>linear</code>
::<var>T</var>&gt;<code>0</code>; <var>T</var> is the (integer) number of averaging cycles
::<math>Y[i,j]_t =
\begin{cases}
\frac{1}{t+1}\sum_{z=0}^t X[i,j]_z & \mbox{if }0\leqslant t < T \\
\frac{1}{T}\sum_{z=0}^{T-1}X[i,j]_{t-z} & \mbox{if }t\geqslant T
\end{cases}
</math>
:;exponential average:
::<var>TYP</var>=<code>1</code> or <code>exponential</code>
::<code>0</code>&lt;<var>T</var>&lt;<code>1</code>; <var>T</var> is the averaging factor
::<math>Y[i,j]_t =
\begin{cases}
X[i,j]_t & \mbox{if }t=0\mbox{ (or }T\mbox{ out of range)}\\
\sqrt{T}.Y[i,j]_{t-1}+(1-\sqrt{T}).X[i,j]_t & \mbox{if }t>0
\end{cases}
</math>
:;minimum:
::<var>TYP</var>=<code>2</code> or <code>minimum</code>
::<var>T</var> is not used
::<math>Y[i,j]_t =
\begin{cases}
X[i,j]_t & \mbox{if }t=0 \\
min(Y[i,j]_{t-1},X[i,j]_t) & \mbox{if }t>0
\end{cases}
</math>
:;maximum:
::<var>TYP</var>=<code>3</code> or <code>maximum</code>
::<var>T</var> is not used
::<math>Y[i,j]_t =
\begin{cases}
X[i,j]_t & \mbox{if }t=0 \\
max(Y[i,j]_{t-1},X[i,j]_t) & \mbox{if }t>0
\end{cases}
</math>
;See also:
;See also:
<[[../#Signal Processing Atoms|SP-atoms]]>
<[[../#Signal Processing Atoms|SP-atoms]]>
<!-- AN, 2.5.2011 -->
<!-- AN, 2.5.2011 -->

Revision as of 13:31, 6 May 2011

Two channel multiplexer.

[SPU SELECTAB A B SEL OUT Y]

input description data type value type default value
A, B input data number, vector variable
SEL select switch number (int.), string variable
output description data type value type comment
Y selected data same type as A variable
Description
SEL Ynumber=f(Anumber,Bnumber) Yvector=f(Avector,Bnumber) Ynumber=f(Avector,Bvector)
0 or A Y = A Y[i] = A[i] Y[i] = A[i]
1 or B Y = B Y[i] = B Y[i] = B[i]
2 or minimum Y = min(A,B) Y[i] = min(A[i],B) Y[i] = min(A[i],B[i])
3 or maximum Y = max(A,B) Y[i] = max(A[i],B) Y[i] = max(A[i],B[i])

with: 0 ≤ i < length of Avector

See also

<SP-atoms>

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