Area under curve with negative X and Y values

I want to use the area() function, but I have negative x and y values on the axes

[Matt J]

And why is that a problem? It seems to work fine.

t=linspace(0,2);area(t,1-t);

[Naomi Amuzie]

I have two vectors for the x and y axes. both contain negative valeus (vectors). Using plot works, using area doesn't.

[Naomi Amuzie]

when attempting to do area(), I get this error:

"Index in position 1 is invalid. Array indices must be positive integers or logical values."

[Star Strider]

Show your vectors and your area call.

This does what we expect it to do:

x = linspace(-5, 0, 5);
y = -x.^2/5;

figure
area(x, y)

[Adam Danz]

Works fine for me (appoximating your data)

x = [-1.25, -.9, -.45, 0]; 
y = [-5.7, -2.5, -.7, 0]; 
subplot(1,2,1)
plot(x,y)
subplot(1,2,2)
area(x,y)

So is must be something else. Please share your code and the input values.

[Walter Roberson]

You have accidentally created a variable named area that is interfering with your call to the area() plot.

[Naomi Amuzie]

the x-axis: [0 -0.650000000000000 -2.60000000000000 -5.60000000000000]

y-axis: [0 -0.422618261740699 -0.845236523481399 -1.26785478522210]

[Walter Roberson]

Run the code. When it stops with an error, show the result for

which -all area

[Naomi Amuzie]

I get what you said, strangely. i don't have a variable named area though...

"area is a variable.

/Applications/MATLAB_R2019a.app/toolbox/matlab/polyfun/@alphaShape/area.m % Shadowed alphaShape method

/Applications/MATLAB_R2019a.app/toolbox/matlab/polyfun/@polyshape/area.m % Shadowed polyshape method

/Applications/MATLAB_R2019a.app/toolbox/coder/half/@half/area.p % Shadowed half method

/Applications/MATLAB_R2019a.app/toolbox/matlab/specgraph/area.m % Shadowed"

[Naomi Amuzie]

Oh! There wasn't a variable in my code, but there was a variable in my workspace I created a long time ago, but never deleted.

Thank you! Sorry about the hassle!