Index exceeds matrix dimensions. Error
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This is the error I receive
_??? Index exceeds matrix dimensions.
Error in ==> CalcPress at 111
P = pb*((tb/(tb + lb(h - hb)))^(g/(Rs*lb)));
Error in ==> P_2_1_1 at 30
[P(j),T(j)] = CalcPress(h);_
Script....................
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
istep = 1000;
imax = 100000;
h = 0;
j = 1;
for i = 0:istep:imax
h = i;
[P(j),T(j)] = CalcPress(h); %%%%line 30 %%%%%%
j = j+1;
end
Function......
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Constants;
EngineSpec;
FlightChar;
lb = 0;
tb = 0;
pb = 0;
hb = 0;
L = [-0.0065,0.0,0.001,0.0028,0.0,-0.0028,-0.002]; %temp lapse rate : K/m
Ts = [288.15,216.65,216.65,228.65,270.65,270.65,214.65]; %standard temp : K
Pa = [101325,22632.1,5474.89,868.019,110.906,66.9389,3.95642]; %static pressure : Pa
H = [0,11000,20000,32000,47000,51000,71000]; %height at b : meters
b = [0,1,2,3,4,5,6];
%%%%%%%%%%Determine proper values of lb, tb, pb, hb %%%%%%%%%%%%%%%%%%%
if h <= H(2)
lb = L(1);
tb = Ts(1);
hb = H(1);
pb = Pa(1);
end
if H(2) <= h <= H(3)
lb = L(2);
tb = Ts(2);
hb = H(2);
pb = Pa(2);
end
if H(3) <= h <= H(4)
lb = L(3);
tb = Ts(3);
hb = H(3);
pb = Pa(3);
end
if H(4) <= h <= H(5)
lb = L(4);
tb = Ts(4);
hb = H(4);
pb = Pa(4);
end
if H(5) <= h <= H(6)
lb = L(5);
tb = Ts(5);
hb = H(5);
pb = Pa(5);
end
if H(6) <= h <= H(7)
lb = L(6);
tb = Ts(6);
hb = H(6);
pb = Pa(6);
end
if H(7) <= h
lb = L(7);
tb = Ts(7);
hb = H(7);
pb = Pa(7);
end
%%%%%%%%%%%%%%%%%%%%%%%%%%% Calc Pressure %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if lb ~= 0
P = pb*((tb/(tb + lb(h - hb)))^(g/(Rs*lb))); %%%line 111 %%%%
end
if lb == 0
P = pb*exp((-g*(h - hb))/(Rs*tb));
end
return;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Any clues on how to fix this error? Appreciate your time and effort!
回答（5 个）
Matthew
2012-2-22
0 个投票
2 个评论
Walter Roberson
2012-2-22
http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup
Rick Rosson
2012-2-22
Thanks!
Walter Roberson
2012-2-22
In your script, before your line
for i = 0:istep:imax
insert the lines
P = zeros(imax+1,1);
T = zeros(imax+1,1);
Walter Roberson
2012-2-23
Note: your expression
H(2) <= h <= H(3)
will be interpreted as
((H(2) <= h) <= H(3))
The first sub-expression is a logical comparison, false (value 0) or true (value 1). The second comparison would then be comparing that 0 or 1 to H(3).
There is no built-in range comparison operator in MATLAB.
Andrei Bobrov
2012-2-24
try variant
% Your Function, input: h
L = [-0.0065,0.0,0.001,0.0028,0.0,-0.0028,-0.002].'; %temp lapse rate : K/m
Ts = [288.15,216.65,216.65,228.65,270.65,270.65,214.65].';%standard temp : K
% static pressure : Pa
Pa = [101325,22632.1,5474.89,868.019,110.906,66.9389,3.95642].';
H = [0,11000,20000,32000,47000,51000,71000].'; %height at b : meters
b = [0,1,2,3,4,5,6];
[bin,bin] = histc(h,[H(:),inf]);
P = zeros(numel(h),1);
lb = L(bin);
x = [L(bin) Ts(bin), H(bin), pb(bin)];
t1 = lb ~= 0;
t2 = ~t1;
x1 = x(t1,:);
x2 = x(t2,:);
P(t1) = x1(:,4).*((x1(:,2)./(x1(:,2) + x1(:,1).*(h - x1(:,3)))).^(g/(Rs*x1(:,1))));
P(t2) = x2(:,4).*exp((-g*(h - x2(:,3)))./(Rs*x2(:,2)));
% Your Script
h = 0:1e3:1e5;
[P,..] = CalcPress(h);
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2013-10-19
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