% DioleFieldProfile extracts profiles in DipolefieldGui
% DipoleFieldProfile is called by DipoleFieldGui

% profilex extracts profile, at spacing sp, from 
% the grid X,Y,Z (same profile from Z1 Z2 if present)
% X,Y,Z should already be contoured in the current figure window
% when profilex is called

%***********************************************************************************
%
%                              Jim Merriam
%                       University of Saskatchewan
%                          jim.merriam@usask.ca
%                              (Jan, 2006)  
%                             
%***********************************************************************************
%  

axes(haxmain)
 axes(haxContour)

set(ProfileHandle,'visible','off')
set(StartTextHandle,'visible','off')
set(EndTextHandle,'visible','off')
set(StartTextHandle1,'visible','off')
set(EndTextHandle1,'visible','off')

disp('EXTRACT A PROFILE FROM THE GRID')
disp('CLICK ON THE BEGINNING AND END POINTS OF THE PROFILE')
[x_x,y_y]=ginput(2);
ll=sqrt((x_x(2)-x_x(1))^2 + (y_y(2)-y_y(1))^2); % length of the profile

sp=1;

nx=round(ll/sp); % num of samples
r=[0:nx]*sp; % sample locations along profile
flip='n'; % flag for profile orientation

  if(x_x(2))<x_x(1)  % if the profile is easternmost to westernmost
  x_x=flipud(x_x);   % flip the ends
  y_y=flipud(y_y);
  r=[nx:-1:0]*sp;    % new sample locations                                      
  flip='y';          % flag that the ends have been flipped
  end                                         

slope=(y_y(2)-y_y(1))/(x_x(2)-x_x(1)); % slope of profile in xy plane
XI=x_x(1)+[0:nx]*sp*cos(atan(slope));  % x locations
YI=y_y(1)+[0:nx]*sp*sin(atan(slope));  % y locations
FI=interp2(X,Y,F,XI,YI,'linear');      % interpolated values


ProfileHandle=plot([x_x(1) x_x(2)],[y_y(1) y_y(2)],'-','LineWidth',2); % plot profile on grid

  if flip=='y';      % if the profile ends were flipped, flip back
  x_x=flipud(x_x);
  y_y=flipud(y_y);
  end                                         

StartTextHandle1=text(x_x(1)+sp,y_y(1)-sp,'START'); % print S(tart) of profile
EndTextHandle1=text(x_x(2)+sp,y_y(2)-sp,'END'); % print E(nd) of profile  

axes(haxmain)
 axes(haxProfile),cla

plot(r,FI,'.-')  % plot profile
xlabel('DISTANCE (grid units)'),ylabel('nT'),title('NEW PROFILE')

set(get(gca,'xlabel'),'fontname','times','fontsize',10);
set(get(gca,'ylabel'),'fontname','times','fontsize',10);
set(get(gca,'zlabel'),'fontname','times','fontsize',10);
set(get(gca,'title'),'fontname','times','fontsize',12);

x=r;  % copy of positions along profile
  if flip=='y';r=fliplr(r); end % if profile ends were flipped, flip r
%StartTextHandle=text(r(1)+sp,FI(1)+(max(FI)-min(FI))/10,'START');          % print S(tart) of profile
%EndTextHandle=text(r(length(r))-sp,FI(1)+(max(FI)-min(FI))/10,'END');  % print E(nd) of profile  
StartTextHandle=text(r(1)+sp,FI(21),'START');          % print S(tart) of profile
EndTextHandle=text(r(length(r))-sp,FI(1)/10,'END');  % print E(nd) of profile