% tasplt.m (aircraft performance chart) ---------------------------
% This script file creates two plots each consisting of 9 traces.
% The following plt tricks and features are demonstrated:
% - Note that these figures plot multiple valued functions (i.e. relations).
% - The first plot (efficiency and range chart) creates a trace for each
% column of gph and mpg (9 columns for 9 altitudes)
% - Demonstrates adding an additional axis to show alternate units on
% the right hand and/or top axis
% - Demonstrates adding text objects to annotate the graph
% - Demonstrates how the cursors in two plots can be linked. Moving
% one, moves the other. Also in this example switching the active
% trace in one plot does the same in the other as well.
% - Uses 'Xstrings' and 'Ystrings' to display alternate units
% - Shows how to close both figures when either plot is closed.
% ----- Author: ----- Paul Mennen
% ----- Email: ----- paul@mennen.org
Pdrag = 44.072e-7; Idrag = 269.46; % parasitic/induced drag coefficients
% change these for a different airplane
alt = 0:4:32; % altitudes (thousands of feet);
sigma = (1-alt/145.442).^4.25588; % density ratio
ymin=50; ymax=186; tas = (ymin:.1:ymax)'; % airspeed range
gph = Pdrag * tas.^3 * sigma + Idrag./(tas * sigma); % power required equation
traceID = reshape(sprintf('%2d,000 ft',alt),9,length(alt))';
traceID(1,:) = 'sea level'; % change '0,000 ft' to 'sea level'
% Now do efficiency and range chart ----------------------------------------------
mpg = repmat(tas,1,length(alt)) ./ gph; % compute efficency (tas/gph)
xmn = 5; xmx = 16; ymx = 14.7;
sz = get(0,'screensize');
wid = min(880,sz(3)-20);
hi = min(600,sz(4)-80); % leave room for the task bar
tg = 'set(findobj(gcf,"tag","ts"),'; % find the alternate axis
ys = '"ylim",get(gca,"ylim")*80,'; % range is 80 times nm/gal (axis limits)
yt = '"ytick",get(gca,"ytick")*80,'; % range is 80 times nm/gal (tick marks)
xs = '"xlim",get(gca,"xlim")*5)'; % percent power is 5 times gph
plt(gph,mpg,...
'FigName','Cessna 185 Efficiency & Range - standard temp (N3946Q)',...
'Xstring','sprintf("%3.1f%% power",5*@XVAL)',...
'Ystring','sprintf("Range: %dnm",round(80*@YVAL))',...
'LabelX','Fuel flow (gph)','AxisPos',[1 1 .94 .95],...
'LabelY','Nautical miles per gallon','TraceID',traceID,...
'Position',[10 45 wid hi],'Options','S-X-Y','AxisCB',[tg ys yt xs]);
% Display 'Percent Power' as an alternative x-axis units above the graph
% Display 'Range' as an alternative y-axis units to the right of the graph
ax1 = gca; hfig = gcf;
ac = get(get(ax1,'ylabel'),'color');
axr = axes('tag','ts','XaxisLoc','top','YaxisLoc','right','pos',get(ax1,'pos'),...
'ticklen',[.002 0],'tickdir','out','xcolor',ac,'ycolor',ac);
set(get(axr,'xlabel'),'string','Percent Power');
set(get(axr,'ylabel'),'string','Range (nm) - assumes 80 gal useable, no reserve');
axes(ax1); % put primary axis on top
% Now do true air speed chart -------------------------------------------------
plt(gph,tas,'Position',[sz(3)-wid-10 sz(4)-hi-80 wid hi],'Options','S-X-Y',...
'FigName','Cessna 185 True Airspeed Chart - standard temp (N3946Q)',...
'AxisCB',[tg xs],'Xstring','sprintf("%3.1f%% power",5*@XVAL)',...
'LabelX','Fuel flow (gph)','AxisPos',[1 1 1 .95],...
'LabelY','True Airspeed (Knots)','TraceID',traceID);
set([text(0,0,'gph = \sigma p V^3 + i / \sigma V'); % Add plot anotation
text(0,0,'where:');
text(0,0,sprintf('p = parasite drag coef = %7.5f\\times10^{-6}',Pdrag*1e6));
text(0,0,sprintf('i = induced drag coef = %7.3f',Idrag));
text(0,0,'\sigma = air density ratio = \rho / \rho_{SL}')],...
{'fontsize'},{13; 9; 12; 12; 12},'units','norm','color',[1 1 .2],...
{'pos'},{[.58 .20]; [.62 .155]; [.62 .12]; [.62 .075]; [.62 .03]});
% Display 'Percent Power' as an alternative x-axis units above the graph
ax2 = gca;
axr = axes('tag','ts','XaxisLoc','top','pos',get(ax2,'pos'),...
'xcolor',ac,'ycolor',get(gcf,'color'));
set(get(axr,'xlabel'),'string','Percent Power');
axes(ax2); % put primary axis on top
% close the 1st plot when the 2nd plot is closed and visa versa
set([gcf hfig],'tag','tas','closeReq','delete(findobj(''tag'',''tas''));');
cid1 = get(ax1,'User'); % get cursor ID for 1st plot
cid2 = get(ax2,'User'); % get cursor ID for 2nd plot
plt('cursor',cid1,'set','xylim',[xmn xmx 9 ymx]); % set plot 1 xy limits
plt('cursor',cid2,'set','xylim',[10 17 115 ymax]); % set plot 2 xy limits
% Cursor movement in 1st plot also moves cursor in 2nd plot and visa versa
s1 = 'plt("cursor",'; s2 = ',"set","activeLine",@LNUM,@IDX);';
plt('cursor',cid1,'set','moveCB',[s1 int2str(cid2) s2]);
plt('cursor',cid2,'set','moveCB',[s1 int2str(cid1) s2]);
