dist.curves.asymm {curveDepth} R Documentation

## Distance for curves

### Description

Calculates distance matrix for two samples of curves using minimax metric. The function can be particularly useful for parallel computation of a big distance matrix.

### Usage

dist.curves.asymm(curvesRows, curvesCols, oneWay = FALSE, verbosity = 0L)


### Arguments

 curvesRows A list where each element is a function being a list containing a matrix coords (values, d columns). curvesCols A list where each element is a function being a list containing a matrix coords (values, d columns). oneWay Whether curves should be condisered as a one-directional, FALSE by default. verbosity Level of reporting messages, the higher the more progress reports are printed, set 0 (default) for no messages.

### Value

A matrix length(curvesRows) x length(curvesCols) with each entry being the distance between two corresponding curves.

### References

Lafaye De Micheaux, P., Mozharovskyi, P. and Vimond, M. (2018). Depth for curve data and applications.

### Examples

library(curveDepth)
# Pixel-grid filling function for an image
plotGridImage <- function(dims){
redDims1 <- dims[1] - 1
redDims2 <- dims[2] - 1
for (i in 1:(dims[1] - 1)){
lines(c(i / redDims1 - 0.5 / redDims1,
i / redDims1 - 0.5 / redDims1),
c(0 - 0.5 / redDims2, 1 + 0.5 / redDims2),
lwd = 1, lty = 3, col = "lightgray")
lines(c(0 - 0.5 / redDims1, 1 + 0.5 / redDims1),
c(i / redDims2 - 0.5 / redDims2,
i / redDims2 - 0.5 / redDims2),
lwd = 1, lty = 3, col = "lightgray")
}
rect(0 - 0.5 / redDims1, 0 - 0.5 / redDims2,
1 + 0.5 / redDims1, 1 + 0.5 / redDims2)
}
# Load two Sevens and one One, plot them,
# and transform to curves
data("mnistShort017")
# First Seven
firstSevenDigit <- mnistShort017$7[, , 5] image(as.matrix(rev(as.data.frame(firstSevenDigit))), col = gray((255:0) / 256), asp = 1, xlim = c(0 - 1 / 27, 1 + 1 / 27), ylim = c(0 - 1 / 27, 1 + 1 / 27)) plotGridImage(dim(firstSevenDigit)[1:2]) firstSevenCurve <- images2curves(array( firstSevenDigit, dim = c(28, 28, 1)))[[1]] # Second Seven secondSevenDigit <- mnistShort017$7[, , 6]
image(as.matrix(rev(as.data.frame(secondSevenDigit))),
col = gray((255:0) / 256), asp = 1,
xlim = c(0 - 1 / 27, 1 + 1 / 27),
ylim = c(0 - 1 / 27, 1 + 1 / 27))
plotGridImage(dim(secondSevenDigit)[1:2])
secondSevenCurve <- images2curves(array(
secondSevenDigit, dim = c(28, 28, 1)))[[1]]
# A One
aOneDigit <- mnistShort017\$1[, , 1]
image(as.matrix(rev(as.data.frame(aOneDigit))),
col = gray((255:0) / 256), asp = 1,
xlim = c(0 - 1 / 27, 1 + 1 / 27),
ylim = c(0 - 1 / 27, 1 + 1 / 27))
plotGridImage(dim(aOneDigit)[1:2])
aOneCurve <- images2curves(array(
aOneDigit, dim = c(28, 28, 1)))[[1]]
# Caculate distances between all the curves
distMatrix <- matrix(0, 3, 3)
distMatrix[3, 1:2] <- distMatrix[1:2, 3] <-
dist.curves.asymm(list(
firstSevenCurve, secondSevenCurve), list(aOneCurve))
distMatrix[2, 1] <- distMatrix[1, 2] <-
dist.curves.asymm(
list(firstSevenCurve), list(secondSevenCurve))
# Print distance matrix
print(distMatrix)


[Package curveDepth version 0.1.0.9 Index]