# How to plot step function \[x\]/x Correctly with limit
**URL:** https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780
**Category:** General Usage
**Tags:** plotting
**Created:** [September 5, 2022, 1:41am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780 "2022-09-05T01:41:20Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)
#### Post date: [September 5, 2022, 1:41am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/1 "2022-09-05T01:41:20Z")
Hi all,
I see a problem set and I want to plot this one:
\frac{[x]}{x}
`[x]` is a step function
I know the code to create step function (from my old thread), but how to create the above function?
```julia
using Plots,LaTeXStrings,Colors
gr()
f(x) = floor(x)
x = 0:1:4
y = f.(x)
plot(x[1:2], [y[1], y[1]], label=L"f(x) = \lfloor x \rfloor", legend=:topleft,legend_foreground_color=:white, legend_font_color=:blue3, color=:blue3, showaxis=false, tickfontcolor=:white)
# axis and
hline!((0,0), color=:black, label="")
vline!((0,0), color=:black, label="")
for i in x
if i!= 0
annotate!(i,-0.2, (i, 7))
end
end
for i in y
if i != 0
annotate!(-.2, i, (i, 7))
end
end
annotate!(-.2, -.2, ("0", 7))
for i in 2:length(x)-1
plot!(x[i:i+1], [y[i], y[i]], label="", color=:blue3, lw=2)
scatter!(x[i], y[i], marker=:circle, markersize=8, label="")
end
scatter!(x[1:end-1], y[1:end-1], markersize=3, markercolor=:blue4, label="")
scatter!(x[2:end], y[1:end-1], markersize=3, markercolor=:white, label="")
```
---
### Author:  [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)
#### Post date: [September 5, 2022, 7:10am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/2 "2022-09-05T07:10:27Z")
Did you mean, this?
```julia
using Plots
saw_blade(x) = floor(x) / x
xspan = 0.01:0.01:10
plot(xspan, saw_blade.(xspan), legend = :none)
```
---
### Author:  [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)
#### Post date: [September 5, 2022, 3:14pm UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/3 "2022-09-05T15:14:33Z")
Is it really works with just `floor(x)`?
Anyway thanks a lot, I just want to admit the first time I saw it just like a shark fin…
---
### Author:  [@gustaphe](https://discourse.julialang.org/u/gustaphe)
#### Post date: [September 5, 2022, 3:26pm UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/4 "2022-09-05T15:26:48Z")
If that is the function you mean, you are not looking for the word “step function”. The step function is `step(x, a=0) = x ≥ a`.
---
### Author:  [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)
#### Post date: [September 6, 2022, 7:22am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/5 "2022-09-06T07:22:32Z")
I try this:
```julia
using Plots, LaTeXStrings
pyplot(fmt=:svg)
step(x, a=0) = x ≥ a
xspan = 0.01:0.01:10
plot(xspan, step.(xspan), legend = :none)
```
I want to divide this `step(x, a=0) = x ≥ a` with `x` and then plot it. Not just plotting the step function.
---
### Author:  [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)
#### Post date: [September 6, 2022, 7:35am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/7 "2022-09-06T07:35:23Z")
This is the plot with expanded domain and codomain
```julia
using Plots, LaTeXStrings
pyplot(fmt=:svg)
saw_blade(x) = floor(x) / x
xspan = -1.0:0.1:5
plot(xspan, step.(xspan), legend = :none)
```
I got it now… if anyone wants to explain it rigorously go ahead… I will love your post.
---
### Author:  [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)
#### Post date: [September 6, 2022, 10:48am UTC](https://discourse.julialang.org/t/how-to-plot-step-function-x-x-correctly-with-limit/86780/8 "2022-09-06T10:48:02Z")
You didn’t use the `saw_blade` function, you used `step.` function in `plot()`.