سلام
برنامه متلب زیر ران می کنم این ارور Undefined function or variable 'c'. میده. میشه راهنماییم کنید؟

function [ vd , vo1 , vh1 , electrode_nodes ] = tanksim ( c , r , x , y , name )
% tanksim utilized the Eidors toolset to simulate
% the voltage measurements for a rectangular tank
% with a 10 electride linear array
ELEC_COUNT = 10;


meter_per_in = 0.0254 ; % meters per inch
salt_water_conductivity = 0.305 ; % ohms meter


tank_dims = [40,40] ; % elements
tank_mdl = mk_common_model ( 'f2s' , ELEC_COUNT ) ;


for ii = 1 : length ( tank_mdl . fwd_model . electrode )
tank_mdl . fwd_model . electrode ( ii ) . nodes = ii*2 + 10;
end
tank_mdl . fwd_model . gnd_node = ii*2 + 10;
tank_shape = [ 30 , 30 ] ; % in
tank_shape = tank_shape*meter_per_in ; % convert to meter
single_element_dim = tank_shape./tank_dims ;
element_conductivity = salt_water_conductivity/single_element_dim (1) ;
bkgnd = element_conductivity ;
fprintf (' Conductivity of Water : %f ' , bkgnd ) ;
img = mk_image ( tank_mdl . fwd_model , bkgnd ) ;
stim = mk_stim_patterns ( ELEC_COUNT , 1 , '{mono}' , '{mono}' ,{} ,1) ;
img . fwd_model . stimulation = stim ;
for i=1: ELEC_COUNT
img.fwd_model.stimulation(i).stim_pattern = [1,zeros(1,ELEC_COUNT-2) , -1]' ;
end
img . fwd_model . meas_select = [ 0 1 ] ;
img_h = img ;
img_o = img ;
select_fcn = Inline(sprintf('( x+%f ).ˆ2+(y+%f).ˆ2<r+%fˆ2' ,x,y,r),'x','y','z');
img_o . elem_data = ( bkgnd*1+(c-bkgnd)*elem_select(img.fwd_model,select_fcn));
winsize = [ 0 0 800 600] ;
f = figure('Position',winsize);
axis tight
img_h.fwd_solve.get_all_meas = 1 ;
vh= fwd_solve ( img_h ) ;
img_o.fwd_solve.get_all_meas = 1 ;
vo= fwd_solve ( img_o ) ;
img_v = rmfield ( img_o , ' elem data ' ) ;
% Show homoeneous image
a = subplot (231) ;
title ( a , ' Object Position ' ) ;
show_fem ( img_o ) ;
axis tight
% Show inhomoeneous image
b = subplot(232) ;
show_current ( img_o,vo.volt( : , 1 ) ) ;
axis tight
title ( b , ' Current Path Tank ' ) ;
axis ([ -1 ,1 , -1 ,1]) ;
% Show difference image
b = subplot(233) ;
img_v . node_data = vh . volt ( : , 1 )-vo . volt ( : , 1 ) ;
img_v . calc_colours . cb_shrink_move =[0.3 ,0.6 , + 0.03] ;
show_current ( img_o , vh . volt ( : , 1 )-vo . volt ( : , 1 ) ) ;
axis tight
title ( b , ' Change in Current Path ' ) ;
axis ([ -1 ,1 ; -1 ,1]) ;
electrode_nodes = [ img . fwd_model . electrode . nodes ] ;
vd = abs(vh.volt(electrode_nodes ,1) - vo.volt ( electrode_nodes , 1 ) ) ;
vh1 = vh.volt( electrode_nodes , 1 ) ;
vh1d = diff(flipud(vh1)) ;
vo1 = diff(flipud( vo.volt(electrode_nodes , 1 ) ) ) ;
title ( ' Differential Current Image ' ) ;
d= subplot ( 2 , 3 , [ 4 , 5 , 6 ] ) ;
bar( vo1-vh1d ) ;
axis tight
vd = vo1-vh1d ;
title ( d , ' Voltage Measured by Electrodes ' ) ;
ylabel ( ' Volts ' ) ;
xlabel ( ' Electrode ID# ' )
ylim ([ -5.5e-4 2.0e-4]) ;
fname = sprintf ( '%s-%dohm m-rod%0.2f-x-%1.1f-y%1.1f' , name , c , r , x , y ) ;
fname = strrep ( fname , ' . ' , ' ' ) ;
saveas ( f , sprintf ( '%s.png' , fname ) , 'png' ) ;
end