From 76177aa280494bb36d7a0bcbda1078d4db717020 Mon Sep 17 00:00:00 2001 From: Ali Labbene Date: Mon, 9 Dec 2019 11:25:19 +0100 Subject: Official ARM version: v4.5 --- .../DSP/html/group___variance_example.html | 157 +++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 Documentation/DSP/html/group___variance_example.html (limited to 'Documentation/DSP/html/group___variance_example.html') diff --git a/Documentation/DSP/html/group___variance_example.html b/Documentation/DSP/html/group___variance_example.html new file mode 100644 index 0000000..f10bf98 --- /dev/null +++ b/Documentation/DSP/html/group___variance_example.html @@ -0,0 +1,157 @@ + + + + + +Variance Example +CMSIS-DSP: Variance Example + + + + + + + + + + + + + + + +
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CMSIS-DSP +  Version 1.4.7 +
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CMSIS DSP Software Library
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Variance Example
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Examples
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Description:
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Demonstrates the use of Basic Math and Support Functions to calculate the variance of an input sequence with N samples. Uniformly distributed white noise is taken as input.
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Algorithm:
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The variance of a sequence is the mean of the squared deviation of the sequence from its mean.
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This is denoted by the following equation: 
 variance = ((x[0] - x') * (x[0] - x') + (x[1] - x') * (x[1] - x') + ... + * (x[n-1] - x') * (x[n-1] - x')) / (N-1)
where, x[n] is the input sequence, N is the number of input samples, and x' is the mean value of the input sequence, x[n].
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The mean value x' is defined as: 
 x' = (x[0] + x[1] + ... + x[n-1]) / N
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Block Diagram:
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+Variance.gif +
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Variables Description:
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  • testInput_f32 points to the input data
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  • wire1, wir2, wire3 temporary buffers
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  • blockSize number of samples processed at a time
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  • refVarianceOut reference variance value
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CMSIS DSP Software Library Functions Used:
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Refer arm_variance_example_f32.c

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