grad_curv – TPGLIB

Routines to calculate surface gradients and curvatures

Uses

- filter
- fftw3
- sort_arrays
- surfile
- data_arch
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Used by

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Graph Key

Nodes of different colours represent the following:

Solid arrows point from a submodule to the (sub)module which it is descended from. Dashed arrows point from a module or program unit to modules which it uses.
Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.

Subroutines

public subroutine curv2(tab, nx, ny, dx, dy, gradxx, gradyy)

Function to calculate the double derivatives of a 2D array

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	tab	input 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along x
real(kind=R8),	intent(in)		::	dx	x lag
real(kind=R8),	intent(in)		::	dy	y lag
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradxx	double derivative along x, x 2D array
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradyy	double derivative along y, y 2D array

public subroutine curvature(tab, nx, ny, dx, dy, S_param_grad, S_param_curv, gcurvt)

Function to calculate the gaussian curvature of a 2D array, its mean quadratic value and the gradient mean quadratic value

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	tab	input 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along x
real(kind=R8),	intent(in)		::	dx	x lag
real(kind=R8),	intent(in)		::	dy	y lag
real(kind=R8),	intent(out)		::	S_param_grad	mean quadratic gradient value
real(kind=R8),	intent(out)		::	S_param_curv	mean quadratic curvature value
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gcurvt	gaussian curvature 2D array

private subroutine deriv_N(x, y, mat_d)

Function to provide the interpolation functions of a QU9 element, as well as its derivatives

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in)		::	x	abscissa between -1 and +1
real(kind=R8),	intent(in)		::	y	ordinate between -1 and +1
real(kind=R8),	intent(out),	dimension(1:9, 1:6)	::	mat_d	array containing N, dN/di, d2N/di2

public subroutine gauss_curv(gradx, grady, nx, ny, dx, dy, gradxx, gradyy, gradxy)

Function to calculate the double derivatives of a 2D array

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	gradx	derivative along x 2D array
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	grady	derivative along y 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along x
real(kind=R8),	intent(in)		::	dx	x lag
real(kind=R8),	intent(in)		::	dy	y lag
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradxx	double derivative along x, x 2D array
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradyy	double derivative along y, y 2D array
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradxy	double derivative along x, y 2D array

public subroutine gradient(tab, nx, ny, dx, dy, gradx, grady)

Function to calculate the gradient of a 2D array

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	tab	Input 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along x
real(kind=R8),	intent(in)		::	dx	x lag
real(kind=R8),	intent(in)		::	dy	y lag
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	gradx	derivative along x 2D array
real(kind=R8),	intent(out),	dimension(1:nx, 1:ny)	::	grady	derivative along y 2D array

private subroutine gradient_corner(hgt, gdx, gdy)

Function that gives the nodal height gradients

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:3, 1:3)	::	hgt	local height 2D array
real(kind=R8),	intent(out),	dimension(1:3)	::	gdx	nodal x gradient
real(kind=R8),	intent(out),	dimension(1:3)	::	gdy	nodal x gradient

public subroutine label_surf_summits(tab, nx, ny, valleys, peaks, saddles, nb_summits)

Function to output the extrema of a 2D array, as peaks, valleys or saddles.

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	tab	input 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along y
integer(kind=I4),	intent(out),	dimension(:,:), allocatable	::	valleys	list of valley coordinates
integer(kind=I4),	intent(out),	dimension(:,:), allocatable	::	peaks	list of peaks coordinates
integer(kind=I4),	intent(out),	dimension(:,:), allocatable	::	saddles	list of saddles coordinates
integer(kind=I4),	intent(out),	dimension(1:3)	::	nb_summits	number of extrema of each kind

private subroutine labelize_point(height, label, x, y)

Function to label a point as: peak, valley, saddle or nothing particular

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=R8),	intent(in),		dimension(1:3, 1:3)	::	height	nodal height values as a 2D array
character(len=1),	intent(out)			::	label	kind of point
real(kind=R8),	intent(out),	optional		::	x	coordinates of the extremum found
real(kind=R8),	intent(out),	optional		::	y	coordinates of the extremum found

public subroutine peaks_and_pits_curvatures(heights, nx, ny, dx, dy, S_param_grad, S_param_curv, peak_curv, pits_curv)

Function to calculate and output the peaks and pits curvatures as well as then mean quadratic gradient value and the mean quadratic curvature value.

Arguments

Type	Intent	Attributes		Name
real(kind=R8),	intent(in),	dimension(1:nx, 1:ny)	::	heights	input 2D array
integer(kind=I4),	intent(in)		::	nx	number of pixels along x
integer(kind=I4),	intent(in)		::	ny	number of pixels along x
real(kind=R8),	intent(in)		::	dx	x lag
real(kind=R8),	intent(in)		::	dy	y lag
real(kind=R8),	intent(out)		::	S_param_grad	mean quadratic gradient value
real(kind=R8),	intent(out)		::	S_param_curv	mean quadratic curvature value
real(kind=R8),	intent(out)		::	peak_curv	3 first peaks mean curvature
real(kind=R8),	intent(out)		::	pits_curv	3 first pits mean curvature

public subroutine test_label_surf_summits()

Function to test the capicity in detecting peaks, pits and saddles in a simple double sinus surface.

Arguments

None

public subroutine test_labelize_point()

Function to test the function “labelize_point” on a QU9 domain with a 2nd order polynomial along x and y

Arguments

None

public subroutine test_peaks_and_pits_curvatures()

Function to test the function “peaks_and_pits_curvatures” on a real rough surface. Outputs surface gradients and curvatures as 2D arrays or single values.

Arguments

None

grad_curv Module

Contents

Subroutines

Uses

Used by

Subroutines

public subroutine curv2(tab, nx, ny, dx, dy, gradxx, gradyy)

Arguments

public subroutine curvature(tab, nx, ny, dx, dy, S_param_grad, S_param_curv, gcurvt)

Arguments

private subroutine deriv_N(x, y, mat_d)

Arguments

public subroutine gauss_curv(gradx, grady, nx, ny, dx, dy, gradxx, gradyy, gradxy)

Arguments

public subroutine gradient(tab, nx, ny, dx, dy, gradx, grady)

Arguments

private subroutine gradient_corner(hgt, gdx, gdy)

Arguments

public subroutine label_surf_summits(tab, nx, ny, valleys, peaks, saddles, nb_summits)

Arguments

private subroutine labelize_point(height, label, x, y)

Arguments

public subroutine peaks_and_pits_curvatures(heights, nx, ny, dx, dy, S_param_grad, S_param_curv, peak_curv, pits_curv)

Arguments

public subroutine test_label_surf_summits()

Arguments

public subroutine test_labelize_point()

Arguments

public subroutine test_peaks_and_pits_curvatures()

Arguments