Dear all,

I have tried `SymPy`

to compute indefinite integral of |x|, this is the code:

```
using SymPy
# we can also use @vars x y z
x = symbols("x")
integrate(abs(x))
```

but the result is like this at terminal, different from the textbook solution:

Dear all,

I have tried `SymPy`

to compute indefinite integral of |x|, this is the code:

```
using SymPy
# we can also use @vars x y z
x = symbols("x")
integrate(abs(x))
```

but the result is like this at terminal, different from the textbook solution:

Please post code and REPL output as text. And what do `include("plot1.jl")`

and `include("plot.jl")`

have to do with anything?

You need to add an assumption, as is implicit in the textbook:

```
julia> @syms x y::real
(x, y)
julia> integrate(abs(x),x)
⌠
⎮ │x│ dx
⌡
julia> integrate(abs(y),y)
⎧ 2
⎪-y
⎪──── for y ≤ 0
⎪ 2
⎨
⎪ 2
⎪ y
⎪ ── otherwise
⎩ 2
```

1 Like

Thanks a lot! I do not know in Julia code I have to do that… put another line for y

It is testing the code I name it `plot.jl`

, and `plot1.jl`

is for other code. Sorry for the confusion.

The point was to show you needed the assumption (::real did that, though you could do it with keywords to symbols).