.TH "MPSCNNSubtractGradient" 3 "Mon Jul 9 2018" "Version MetalPerformanceShaders-119.3" "MetalPerformanceShaders.framework" \" -*- nroff -*-
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.SH NAME
MPSCNNSubtractGradient
.SH SYNOPSIS
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\fC#import <MPSCNNMath\&.h>\fP
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Inherits \fBMPSCNNArithmeticGradient\fP\&.
.SS "Instance Methods"

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.RI "(nonnull instancetype) \- \fBinitWithDevice:isSecondarySourceFilter:\fP"
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.SS "Additional Inherited Members"
.SH "Detailed Description"
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This depends on Metal\&.framework\&.  Specifies the subtraction gradient operator\&. This arithmetic gradient filter requires the following inputs: gradient image from the previous layer (going backwards) and either the primary or the secondary source image from the forward pass\&. You will need a separate filter for the primary and secondary source images\&.
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Without broadcasting, the arithmetic subtract gradient operation for the primary source image is a copy operation on the input gradient image (for x - y, d/dx(x - y) = 1)\&. This copy operation can be optimized away by the graph interface\&.
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For the secondary source image, the result is a negation of the gradient image from the previous layer (for x - y, d/dy(x - y) = -1)\&.
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Setting the broadcasting parameters results in a reduction operation (sum) across all of the applicable broadcasting dimensions (rows, columns, feature channels, or any combination thereof) to produce the destination image of the size that matches the primary/secondary input images used in the forward pass\&. 
.SH "Method Documentation"
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.SS "\- (nonnull instancetype) \fBinitWithDevice:\fP (nonnull id< MTLDevice >) device(BOOL) isSecondarySourceFilter"
Initialize the subtraction gradient operator\&. 
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\fBParameters:\fP
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\fIdevice\fP The device the filter will run on\&. 
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\fIisSecondarySourceFilter\fP \fBA\fP boolean indicating whether the arithmetic gradient filter is operating on the primary or secondary source image from the forward pass\&. 
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\fBReturns:\fP
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\fBA\fP valid \fBMPSCNNSubtractGradient\fP object or nil, if failure\&. 
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Reimplemented from \fBMPSCNNArithmeticGradient\fP\&.

.SH "Author"
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Generated automatically by Doxygen for MetalPerformanceShaders\&.framework from the source code\&.