I am using Plotlyjs here, `gr()`

can also be used, but can’t be rotated.

I want to create a hayshed that will look like this:

I have come up with this code:

```
# Inverted catenary
using Plots;
#gr()
plotlyjs()
# a large hayshed of length 100 feet and width 48 feet is built
# a cross section has the shape of an inverted catenary with equation y = 37 - 24 cosh (x/24)
# ones(m) = m-element row vector (m x 1) with entries of 1
# ones(m,n) = m times n matrix with entries of 1
# range(0, 2π; length = n) = initial 0 till 2π partitioned n times
# θ' = 1x130 vector column with entries θ
# ones(m)*θ' -> becomes m x dim(θ') matrix
# cosh.(ones(m)*θ') -> compute cosh for every entries in matrix (ones(m)*θ')
function hayshedcatenary(r)
m = 200
n = 130
h = 100 # length 100 feet
θ = range(0, 2π; length = n)
w = range(0, 48; length = n)
t = range(0, h; length = m)
x = ones(m)*w'
y = t * ones(n)'
z = 37*ones(m,n) - 24cosh.(ones(m)*(θ/24)')
return x, y, z
end
my_cg = cgrad([:green,:blue])
surface(hayshedcatenary(3), label="hayshed")
```

There is a slight missing, on the vertical / y-axis it should be from 0 to 13, I follow the equation carefully, if there is something wrong with this:

`37*ones(m,n) - 24cosh.(ones(m)*(θ/24)')`

?

The x axis in the picture is from -24 to 24, can we modify the code so it will goes form -24 to 24 as well? instead of 0 to 48.

**Edited,** fix the x axis with: `w = range(-24, 24; length = n)`

and I fix the y-axis with:

```
function hayshedcatenary(r)
m = 200
n = 130
h = 100 # length 100 feet
w = range(-24, 24; length = n)
t = range(0, h; length = m)
x = ones(m)*w'
y = t * ones(n)'
z = 37*ones(m,n) - 24cosh.(ones(m)*(w/24)')
return x, y, z
end
```

Thanks.