# This script exercises an error that occurs when:
# - using a helper function (_sumh) to compute an iterative summation of a term
# - to produce a graph with ezmesh
#
# The output, including the error message is shown in the comment below

#----------------- output ------------------
# ans = -1.0733
# ans = -18.272
# ans =  1.4576e-12
# ans =  1.3531
# error: _sumh: operator +: nonconformant arguments (op1 is 60x60, op2 is 1x9)
# error: evaluating argument list element number 1
# error: called from:
# error:   _sumh at line 30, column 5
# error: evaluating argument list element number 1
# error:   C at line 26, column 5
# error:   /usr/share/octave/3.6.4/m/plot/private/__ezplot__.m at line 402, column 11
# error:   /usr/share/octave/3.6.4/m/plot/ezmesh.m at line 73, column 19
# error:   /home/erik/Develop/dispoctave/test/_sumh/exercise.m at line 49, column 1
#-------------- end of output ---------------

clear all;

function rv = C(x,t)
	rv = 2.*x.*sum(_sumh(x,t, -4:4));
endfunction

function rv = _sumh(x,t, it)
	rv = exp(-(x.+(it.-1./2)).^2./t);
endfunction

#
# Show that the functions work with a single invocation.
# (at the corners of the (x,t) domain, used by the graph below)
#
C(-5,1)
C(-5,10)
C(10,1)
C(10,10)

#
# Create a graph, using ezmesh
#
domain = [-5, 10, 1, 10];
graphics_toolkit gnuplot
setenv GNUTERM wxt
fh = @(x,t) C(x,t);
ezmesh (fh, domain);

# EOF