kernDiagGradX {tigre} | R Documentation

## Compute the gradient of the kernel wrt X.

### Description

computes the gradient of the (diagonal of the) kernel matrix with respect to the elements of the design matrix given in X.

### Usage

      kernDiagGradX(kern, x)
      kernGradX(kern, x, x2)

### Arguments

`kern` | the kernel structure for which gradients are being computed.
`x` | if only argument: the input data in the form of a design matrix, if two arguments: row locations against which gradients are being computed.
`x2` | (optional) column locations against which gradients are being computed.

### Value

`gX` | the gradients of the diagonal with respect to each element of X. The returned matrix has the same dimensions as X.
`gX2` | the returned gradients. The gradients are returned in a matrix which is numData x numInputs x numData. Where numData is the number of data points and numInputs is the number of input dimensions in X.

### See Also

`kernGradient`

### Examples

    kern <- kernCreate(1, 'mlp')
    g <- kernDiagGradX(kern, as.matrix(3:8))

[Package tigre version 1.40.0 Index]