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comparison scripts/ode/private/runge_kutta_45_dorpri.m @ 30893:e1788b1a315f

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maint: Use "fcn" as preferred abbreviation for "function" in m-files. * accumarray.m, accumdim.m, quadl.m, quadv.m, randi.m, structfun.m, __is_function__.m, uigetfile.m, uimenu.m, uiputfile.m, doc_cache_create.m, colorspace_conversion_input_check.m, imageIO.m, argnames.m, vectorize.m, vectorize.m, normest1.m, inputname.m, nthargout.m, display_info_file.m, decic.m, ode15i.m, ode15s.m, ode23.m, ode23s.m, ode45.m, odeset.m, check_default_input.m, integrate_adaptive.m, ode_event_handler.m, runge_kutta_23.m, runge_kutta_23s.m, runge_kutta_45_dorpri.m, runge_kutta_interpolate.m, starting_stepsize.m, __all_opts__.m, fminbnd.m, fminsearch.m, fminunc.m, fsolve.m, fzero.m, sqp.m, fplot.m, plotyy.m, __bar__.m, __ezplot__.m, flat_entry.html, profexport.m, movfun.m, bicg.m, bicgstab.m, cgs.m, eigs.m, gmres.m, pcg.m, __alltohandles__.m, __sprand__.m, qmr.m, tfqmr.m, dump_demos.m: Replace "func", "fun", "fn" in documentation and variable names with "fcn".
author Rik <rik@octave.org>
date Mon, 04 Apr 2022 18:14:56 -0700
parents 796f54d4ddbf
children 597f3ee61a48
comparison
equal deleted inserted replaced
30892:1a3cc2811090 30893:e1788b1a315f
22 ## <https://www.gnu.org/licenses/>. 22 ## <https://www.gnu.org/licenses/>.
23 ## 23 ##
24 ######################################################################## 24 ########################################################################
25 25
26 ## -*- texinfo -*- 26 ## -*- texinfo -*-
27 ## @deftypefn {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fun}, @var{t}, @var{x}, @var{dt}) 27 ## @deftypefn {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fcn}, @var{t}, @var{x}, @var{dt})
28 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fun}, @var{t}, @var{x}, @var{dt}, @var{options}) 28 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fcn}, @var{t}, @var{x}, @var{dt}, @var{options})
29 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fun}, @var{t}, @var{x}, @var{dt}, @var{options}, @var{k_vals}) 29 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fcn}, @var{t}, @var{x}, @var{dt}, @var{options}, @var{k_vals})
30 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fun}, @var{t}, @var{x}, @var{dt}, @var{options}, @var{k_vals}, @var{t_next}) 30 ## @deftypefnx {} {[@var{t_next}, @var{x_next}] =} runge_kutta_45_dorpri (@var{@@fcn}, @var{t}, @var{x}, @var{dt}, @var{options}, @var{k_vals}, @var{t_next})
31 ## @deftypefnx {} {[@var{t_next}, @var{x_next}, @var{x_est}] =} runge_kutta_45_dorpri (@dots{}) 31 ## @deftypefnx {} {[@var{t_next}, @var{x_next}, @var{x_est}] =} runge_kutta_45_dorpri (@dots{})
32 ## @deftypefnx {} {[@var{t_next}, @var{x_next}, @var{x_est}, @var{k_vals_out}] =} runge_kutta_45_dorpri (@dots{}) 32 ## @deftypefnx {} {[@var{t_next}, @var{x_next}, @var{x_est}, @var{k_vals_out}] =} runge_kutta_45_dorpri (@dots{})
33 ## 33 ##
34 ## This function can be used to integrate a system of ODEs with a given initial 34 ## This function can be used to integrate a system of ODEs with a given initial
35 ## condition @var{x} from @var{t} to @var{t+dt} with the Dormand-Prince method. 35 ## condition @var{x} from @var{t} to @var{t+dt} with the Dormand-Prince method.
65 ## 65 ##
66 ## Fourth output parameter is matrix containing the Runge-Kutta evaluations 66 ## Fourth output parameter is matrix containing the Runge-Kutta evaluations
67 ## to use in an FSAL scheme or for dense output. 67 ## to use in an FSAL scheme or for dense output.
68 ## @end deftypefn 68 ## @end deftypefn
69 69
70 function [t_next, x_next, x_est, k] = runge_kutta_45_dorpri (fun, t, x, dt, 70 function [t_next, x_next, x_est, k] = runge_kutta_45_dorpri (fcn, t, x, dt,
71 options = [], 71 options = [],
72 k_vals = [], 72 k_vals = [],
73 t_next = t + dt) 73 t_next = t + dt)
74 74
75 ## Reference: Hairer, Ernst; Nørsett, Syvert Paul; Wanner, Gerhard (2008), 75 ## Reference: Hairer, Ernst; Nørsett, Syvert Paul; Wanner, Gerhard (2008),
98 endif 98 endif
99 99
100 if (! isempty (k_vals)) # k values from previous step are passed 100 if (! isempty (k_vals)) # k values from previous step are passed
101 k(:,1) = k_vals(:,end); # FSAL property 101 k(:,1) = k_vals(:,end); # FSAL property
102 else 102 else
103 k(:,1) = feval (fun, t, x, args{:}); 103 k(:,1) = feval (fcn, t, x, args{:});
104 endif 104 endif
105 105
106 k(:,2) = feval (fun, s(2), x + k(:,1) * aa(2, 1).' , args{:}); 106 k(:,2) = feval (fcn, s(2), x + k(:,1) * aa(2, 1).' , args{:});
107 k(:,3) = feval (fun, s(3), x + k(:,1:2) * aa(3, 1:2).', args{:}); 107 k(:,3) = feval (fcn, s(3), x + k(:,1:2) * aa(3, 1:2).', args{:});
108 k(:,4) = feval (fun, s(4), x + k(:,1:3) * aa(4, 1:3).', args{:}); 108 k(:,4) = feval (fcn, s(4), x + k(:,1:3) * aa(4, 1:3).', args{:});
109 k(:,5) = feval (fun, s(5), x + k(:,1:4) * aa(5, 1:4).', args{:}); 109 k(:,5) = feval (fcn, s(5), x + k(:,1:4) * aa(5, 1:4).', args{:});
110 k(:,6) = feval (fun, s(6), x + k(:,1:5) * aa(6, 1:5).', args{:}); 110 k(:,6) = feval (fcn, s(6), x + k(:,1:5) * aa(6, 1:5).', args{:});
111 111
112 ## compute new time and new values for the unknowns 112 ## compute new time and new values for the unknowns
113 ## t_next = t + dt; 113 ## t_next = t + dt;
114 x_next = x + k(:,1:6) * cc(:); # 5th order approximation 114 x_next = x + k(:,1:6) * cc(:); # 5th order approximation
115 115
116 ## if the estimation of the error is required 116 ## if the estimation of the error is required
117 if (nargout >= 3) 117 if (nargout >= 3)
118 ## new solution to be compared with the previous one 118 ## new solution to be compared with the previous one
119 k(:,7) = feval (fun, t_next, x_next, args{:}); 119 k(:,7) = feval (fcn, t_next, x_next, args{:});
120 cc_prime = dt * c_prime; 120 cc_prime = dt * c_prime;
121 x_est = x + k * cc_prime(:); 121 x_est = x + k * cc_prime(:);
122 endif 122 endif
123 123
124 endfunction 124 endfunction