I got the problem with polyshape, please help me

조회 수: 16 (최근 30일)
Thai Anh
Thai Anh 2022년 12월 4일
편집: Stephan 2022년 12월 5일
Demand: sketch the domain D be the region bounded by
My code:
x1 = 0:1:30;
y1 = 2-x1;
y2 = sqrt(x1).*(12-x1)./2;
xcut = fzero(@(x)sqrt(x).*(12-x)./2 - 2+x, 0.5);
x = [x1(x1<=xcut), x1(end)];
y = [sqrt(x1).*(12-x1)./2 (x1<=xcut), 2-x1(end)];
M = polyshape(x,y);
plot(x1,y1,x1,y2,x,y)
hold on
plot(M)
hold off
xlim([0,30])
ylim([0,30])
Error:
Error using polyshape/getXY
x- and y-coordinates must be vectors of the same size with at least 3 elements.
Error in polyshape/checkInput (line 842)
[X, Y, xy2input, next_arg] = polyshape.getXY(varargin{:});
Error in polyshape (line 169)
[X, Y, tc, simpl, collinear] = polyshape.checkInput(param, varargin{:});
Error in bai4 (line 7)
M = polyshape(x,y);
  댓글 수: 4
Thai Anh
Thai Anh 2022년 12월 4일
@John D'Errico can you help me to fix it
Thai Anh
Thai Anh 2022년 12월 4일
oh I'm sorry.
The demand is sketch the domain D be the region bounded by

댓글을 달려면 로그인하십시오.

채택된 답변

Stephan
Stephan 2022년 12월 4일
You have to take both points into account to find a closed region:
xcut1 = fzero(@(x)sqrt(x).*(12-x)./2 - 2+x, 0.5);
xcut2 = fzero(@(x)sqrt(x).*(12-x)./2 - 2+x, 20);
I had the code ready here - but homework is homework... I leave the rest to you. It should be easy now...
  댓글 수: 12
Thai Anh
Thai Anh 2022년 12월 5일
x1 = 0:1:30;
y1 = 2-x1;
y2 = sqrt(x1).*(12-x1)./2;
xcut1 = fzero(@(x)sqrt(x).*(12-x)./2 - 2+x, 0.5);
xcut2 = fzero(@(x)sqrt(x).*(12-x)./2 - 2+x, 20);
a=[x1(xcut1<=x1),x1(x1<=xcut2)];
b=[2-x1 (x1>=xcut1), 2-x1 (x1<=xcut2)] ;
M = polyshape(a,b);
plot(M)
hold on;
grid on;
xlim([0,30])
ylim([0,30])
..... I tried but I cannot mark the curve region
Stephan
Stephan 2022년 12월 5일
편집: Stephan 2022년 12월 5일
Sorry, last try - i can not make it more clear without doing your homework:
x = -10:1:10;
y1 = -x.^2 + 100;
y2 = 0.*x + 50;
xcut1 = fzero(@(x)-x.^2 + 100 - 50,-7);
xcut2 = fzero(@(x)-x.^2 + 100 - 50,7);
x_linear = [xcut1 xcut2];
y_linear = [50 50];
x_quad = linspace(xcut1, xcut2, 25);
y_quad = -x_quad.^2 + 100;
M = polyshape([x_linear, x_quad], [y_linear, y_quad],'simplify', false);
plot(x,y1,x,y2)
hold on
plot(M)

댓글을 달려면 로그인하십시오.

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Numerical Integration and Differential Equations에 대해 자세히 알아보기

태그

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by