sufr_interpolate Module Reference

Procedures to do interpolation (and fitting?) More...

Functions/Subroutines
pure real(double) function	linear_interpolation (x1, x2, y1, y2, x)
	Do linear interpolation using the data points x1,x2, and y1,y2 to find the value y corresponding to x.
pure real function	linear_interpolation_sp (x1, x2, y1, y2, x)
	Do linear interpolation using the data points x1,x2, and y1,y2 to find the value y corresponding to x, using single-precision variables.
real(double) function	linear_interpolate_array (xarr, yarr, xval)
	Do linear interpolation using the data arrays xArr,yArr to find the value y corresponding to x.
pure subroutine	perfect_parabolic_fit (x1, x2, x3, y1, y2, y3, a, b, c)
	Fit a parabola perfectly to three sets of data points x1,y1, x2,y2 and x3,y3.
pure real(double) function	parabola (x, a, b, c)
	Compute a parabola a*x^2 + b*x + c.
pure integer function	locate_value_in_array (xval, xarray)
	Locate the index in a monotonic array, such that a given value lies between array(index) and array(index+1). 0 or nArr+1 is returned if the value lies outside the array.

Detailed Description

Procedures to do interpolation (and fitting?)

Function/Subroutine Documentation

linear_interpolate_array()

real(double) function sufr_interpolate::linear_interpolate_array	(	real(double), dimension(:), intent(in)	xarr,
		real(double), dimension(:), intent(in)	yarr,
		real(double), intent(in)	xval )

Do linear interpolation using the data arrays xArr,yArr to find the value y corresponding to x.

Parameters

xArr	X-array, sorted to increasing value
yArr	Y-array
xVal	X value to find y value for

Return values

linear_interpolate_array

Y value found

Definition at line 91 of file interpolate.f90.

References sufr_kinds::double, linear_interpolate_array(), linear_interpolation(), locate_value_in_array(), and sufr_system::warn().

Referenced by linear_interpolate_array().

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linear_interpolation()

pure real(double) function sufr_interpolate::linear_interpolation	(	real(double), intent(in)	x1,
		real(double), intent(in)	x2,
		real(double), intent(in)	y1,
		real(double), intent(in)	y2,
		real(double), intent(in)	x )

Do linear interpolation using the data points x1,x2, and y1,y2 to find the value y corresponding to x.

Parameters

x1	X value 1
x2	X value 2
y1	Y value 1, belonging to x1
y2	Y value 2, belonging to x2
x	X value to find y value for

Return values

linear_interpolation

Y value found

Definition at line 41 of file interpolate.f90.

References sufr_kinds::double, and linear_interpolation().

Referenced by linear_interpolate_array(), linear_interpolation(), and linear_interpolation_sp().

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linear_interpolation_sp()

pure real function sufr_interpolate::linear_interpolation_sp	(	real, intent(in)	x1,
		real, intent(in)	x2,
		real, intent(in)	y1,
		real, intent(in)	y2,
		real, intent(in)	x )

Do linear interpolation using the data points x1,x2, and y1,y2 to find the value y corresponding to x, using single-precision variables.

Parameters

x1	X value 1
x2	X value 2
y1	Y value 1, belonging to x1
y2	Y value 2, belonging to x2
x	X value to find y value for

Return values

linear_interpolation_sp

Y value found

Definition at line 70 of file interpolate.f90.

References linear_interpolation(), and linear_interpolation_sp().

Referenced by linear_interpolation_sp().

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locate_value_in_array()

pure integer function sufr_interpolate::locate_value_in_array	(	real(double), intent(in)	xval,
		real(double), dimension(:), intent(in)	xarray )

Locate the index in a monotonic array, such that a given value lies between array(index) and array(index+1). 0 or nArr+1 is returned if the value lies outside the array.

Parameters

xVal	Value to locate
xArray	Array to locate value in. xArray must be monotonic, either ascending or descending

Return values

locate_value_in_array

Index such that the value lies between array(index) and array(index+1).

See also

Numerical Recipes in Fortran, Sect.3.4

Definition at line 181 of file interpolate.f90.

References sufr_numerics::deq(), sufr_kinds::double, and locate_value_in_array().

Referenced by linear_interpolate_array(), and locate_value_in_array().

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parabola()

pure real(double) function sufr_interpolate::parabola	(	real(double), intent(in)	x,
		real(double), intent(in)	a,
		real(double), intent(in)	b,
		real(double), intent(in)	c )

Compute a parabola a*x^2 + b*x + c.

Parameters

x	X value
a	Coefficient a in y = a*x^2 +b*x + c
b	Coefficient b in y = a*x^2 +b*x + c
c	Coefficient c in y = a*x^2 +b*x + c

Return values

parabola

The value of the parabola at x.

Definition at line 158 of file interpolate.f90.

References sufr_kinds::double, and parabola().

Referenced by parabola().

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perfect_parabolic_fit()

pure subroutine sufr_interpolate::perfect_parabolic_fit	(	real(double), intent(in)	x1,
		real(double), intent(in)	x2,
		real(double), intent(in)	x3,
		real(double), intent(in)	y1,
		real(double), intent(in)	y2,
		real(double), intent(in)	y3,
		real(double), intent(out)	a,
		real(double), intent(out)	b,
		real(double), intent(out)	c )

Fit a parabola perfectly to three sets of data points x1,y1, x2,y2 and x3,y3.

Parameters

x1	X value 1
x2	X value 2
x3	X value 3
y1	Y value 1, belonging to x1
y2	Y value 2, belonging to x2
y3	Y value 3, belonging to x3
a	Coefficient a in y = a*x^2 + b*x + c (output)
b	Coefficient b in y = a*x^2 + b*x + c (output)
c	Coefficient c in y = a*x^2 + b*x + c (output)

Definition at line 127 of file interpolate.f90.

References sufr_kinds::double.