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200 | with System ;
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Text_IO.C_Streams;
with Ada.Long_Float_Text_IO; use Ada.Long_Float_Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
with Interfaces.C; use Interfaces.C;
with Interfaces.C.Strings; use Interfaces.C.Strings;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Command_Line; use Ada.Command_Line;
with Ada.Numerics.Elementary_Functions ; use Ada.Numerics.Elementary_Functions;
with GNAT.Source_Info; use GNAT.Source_Info;
with gsl ;
with gsl.interp ;
with gsl.spline ;
-- 30.7 1D Interpolation Example Programs
procedure Interp2d is
use gsl.double_text_io;
Verbose : boolean := True ;
Status : Int ;
procedure Test1 is
myname : String := gnat.Source_Info.enclosing_entity ;
logfile : File_Type ;
N : constant := 10 ;
x,y : gsl.double_array(1..N);
acc : access gsl.interp.gsl_interp_accel := gsl.interp.accel_alloc ;
spline : access gsl.spline.gsl_spline := gsl.spline.alloc(gsl.interp.gsl_interp_akima,N);
xi, yi,xdelta : double ;
begin
if Verbose
then
Put_Line(myname);
end if ;
Create(logfile,Out_File,myname & ".csv");
Set_Output(logfile);
for i in 1..N
loop
x(i) := double(i) + double( 0.5 * Sin(Float(i))) ;
y(i) := double(i) + double( Cos(Float(i)) * Cos(Float(i))) ;
Put(x(i)) ; Put(" ; ");
Put(y(i)) ;
New_Line;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
Status := gsl.spline.init(spline,x,y,N);
Create(logfile,Out_File,myname & ".interp.csv");
Set_Output(logfile);
xi := x(x'First) ;
xdelta := 0.1 ;
loop
if xi >= x(x'Last)
then
exit ;
end if ;
yi := gsl.spline.eval(spline,xi,acc) ;
Put(xi) ; Put(" ; ");
Put(yi) ;
New_Line ;
xi := xi + xdelta ;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
end Test1 ;
procedure Test2 is
-- a periodic cubic spline with 4 data points
myname : String := gnat.Source_Info.enclosing_entity ;
logfile : File_Type ;
N : constant := 4 ;
NP : constant := 100 ;
x : gsl.double_array := (0.00, 0.10, 0.27, 0.30) ;
y : gsl.double_array := (0.15, 0.70, -0.10, 0.15) ;
xi, yi : double ;
xdelta : double := 0.1 ;
acc : access gsl.interp.gsl_interp_accel := gsl.interp.accel_alloc ;
spline : access gsl.spline.gsl_spline :=
gsl.spline.alloc(gsl.interp.gsl_interp_cspline_periodic,N);
begin
if Verbose
then
Put_Line(myname);
end if ;
Create(logfile,Out_File,myname & ".csv");
Set_Output(logfile);
for i in 1..N
loop
Put(x(i)) ; Put(" ; ");
Put(y(i)) ;
New_Line;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
Status := gsl.spline.init(spline,x,y,N);
Create(logfile,Out_File,myname & ".interp.csv");
Set_Output(logfile);
xi := x(x'First) ;
xdelta := (x(x'Last) - x(x'First)) / double(NP) ;
for i in 1..NP
loop
if xi >= x(x'Last)
then
exit ;
end if ;
yi := gsl.spline.eval(spline,xi,acc) ;
Put(xi) ; Put(" ; ");
Put(yi) ;
New_Line ;
xi := xi + xdelta ;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
end Test2 ;
procedure Test3 is
-- Different techniques of interpolation on difficult dataset
myname : String := gnat.Source_Info.enclosing_entity ;
logfile : File_Type ;
-- this dataset is taken from
-- J. M. Hyman, Accurate Monotonicity preserving cubic interpolation,
-- * SIAM J. Sci. Stat. Comput. 4, 4, 1983.
x : gsl.double_array := ( 7.99, 8.09, 8.19, 8.7, 9.2,
10.0, 12.0, 15.0, 20.0 ) ;
y : gsl.double_array := ( 0.0, 2.76429e-5, 4.37498e-2,
0.169183, 0.469428, 0.943740,
0.998636, 0.999919, 0.999994 );
N : size_t := size_t(x'Length) ;
acc : access gsl.interp.gsl_interp_accel := gsl.interp.accel_alloc ;
cubic_spline : access gsl.spline.gsl_spline :=
gsl.spline.alloc(gsl.interp.gsl_interp_cspline,N);
akima_spline : access gsl.spline.gsl_spline :=
gsl.spline.alloc(gsl.interp.gsl_interp_akima,N);
steffen_spline : access gsl.spline.gsl_spline :=
gsl.spline.alloc(gsl.interp.gsl_interp_steffen,N);
NP : constant := 100 ;
xi, yi : double ;
xdelta : double ;
begin
if Verbose
then
Put_Line(myname);
end if ;
Create(logfile,Out_File,myname & ".csv");
Set_Output(logfile);
for i in 1..Integer(N)
loop
Put(x(i)) ; Put(" ; ");
Put(y(i)) ;
New_Line;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
Status := gsl.spline.init(cubic_spline,x,y,N);
Status := gsl.spline.init(akima_spline,x,y,N);
Status := gsl.spline.init(steffen_spline,x,y,N);
Create(logfile,Out_File,myname & ".interp.csv");
Set_Output(logfile);
xi := x(x'First) ;
xdelta := (x(x'Last) - x(x'First)) / double(NP) ;
for i in 1..NP
loop
if xi >= x(x'Last)
then
exit ;
end if ;
Put(xi) ; Put(" ; ");
yi := gsl.spline.eval(cubic_spline,xi,acc) ; Put(yi) ; Put(" ; ");
yi := gsl.spline.eval(akima_spline,xi,acc) ; Put(yi) ; Put(" ; ");
yi := gsl.spline.eval(steffen_spline,xi,acc) ; Put(yi) ; Put(" ; ");
New_Line ;
xi := xi + xdelta ;
end loop ;
Set_Output(Standard_Output);
Close(logfile);
end Test3 ;
begin
Test1 ;
Test2 ;
Test3 ;
end Interp2d ;
|