Topic: Spatial
Topic Description:
Functions for calculating Ripley's K from CTFS R Analytical Tables, many routines for quadrat-based calculations. and calculations of wavelet variance.
File: spatial/slope.r
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Function: calcslope
Function Description: calcslope
None provided.Function Arguments:
| Argument | Default Value |
|---|---|
| z | |
| gridsize | 20 |
| z | |
| gridsize | 20 |
Function Source:
calcslope=function(z, gridsize=20)
{
z2=z[3]-z[2]
z1=z[1]-z[2]
if(z2==0)
{
if(z1==0) return(0)
else denom=sqrt( 1+(gridsize/z1)^2 )
theta1 = acos( (-gridsize/z1)/denom )
theta2 = acos( (gridsize/z1)/denom )
}
else
{
denom = sqrt( 1+(z1/z2)^2+(gridsize/z2)^2 )
theta1 = acos( (-gridsize/z2)/denom )
theta2 = acos( (gridsize/z2)/denom )
}
if(theta1<=theta2) return(180*theta1/pi)
else return(180*theta2/pi)
}
{
z2=z[3]-z[2]
z1=z[1]-z[2]
if(z2==0)
{
if(z1==0) return(0)
else denom=sqrt( 1+(gridsize/z1)^2 )
theta1 = acos( (-gridsize/z1)/denom )
theta2 = acos( (gridsize/z1)/denom )
}
else
{
denom = sqrt( 1+(z1/z2)^2+(gridsize/z2)^2 )
theta1 = acos( (-gridsize/z2)/denom )
theta2 = acos( (gridsize/z2)/denom )
}
if(theta1<=theta2) return(180*theta1/pi)
else return(180*theta2/pi)
}