cmdplot.mtr
native plot()
native table()
export [plot, table] as cmdplot
The cmdplot module allows you to display plots and tables in the console.
It is highly reccomended to view this chapter with the local Menter server running.
plot
The plot function takes a width, a height, a list of x values and functions to calculate y values from x values. It then prints a plot of the functions to the default print stream.
Alternatively, a list of x values and a list of y values can be passed. In this case, no values will be calculated from the x values.
If not enough values are passed to fill every x position, a linearly interpolated line will be used to fill the gaps.
import cmdplot inline
width = 90
height = 12;;;plot(
width, height, # actual dimensions of the plot on the console
space(-2 * PI, 2 * PI, width), # x values
sin # multiple functions to calculate y values from x values
)
With a list of x values and a list of y values:
import cmdplot inline
width = 90
height = 12;;;plot(
width, height,
[1, 3, 6, -4], # x values
[-4, 3, 7, 5] # y values
)
Some more examples
Two functions in one plot:
import cmdplot inline
width = 90
height = 25;;;plot(
width, height,
space(-14, 23, width),
x -> (x - 1) * (x + 9) * ((x - 15)^^2),
x -> -100 * ((x- 6)^^2) + 30000
)
Calculating the approximate derivative of a function:
import cmdplot inline
derivative = (p, f) -> (x -> (f(x+p) - f(x-p)) / (2*p));;;plot(
90, 20,
space(1, 3 * PI),
sin,
derivative(0.1, sin)
);;;plot(
90, 20,
space(-5, 5),
x -> x^^3,
derivative(0.1, x -> x^^3)
)
A beautiful circle:
import cmdplot;;;generate_points = r -> {
p.x = []
p.y = []
for (i in space(0, 2 * PI, 360)) {
p.x = p.x :: (r * cos(i))
p.y = p.y :: (r * sin(i))
}
return p
};;;points = generate_points(10);;;cmdplot.plot(62, 25, points.x, points.y)
table
The table function takes an object and prints attributes in a formatted table to the default print stream.
This table has two modes, depending on the type of the object that is passed to it:
List of objects:
import cmdplot inline;;;table([
{ name: "Yan", age: 23 },
{ name: "Thomas", age: 24 }
])
Object of lists/values:
import cmdplot inline;;;table({A: [1, 2, 3], B: [4, 5], C: 6})
Here is a more complicated example with an object:
import cmdplot inline;;;names = ["Yan", "Thomas", "John", "Mira", "Daniel", "Viola"];;;pick(list) = list[floor(random(0, names.size()))];;;createPerson(min, max) = {
name: pick(names),
age: round(random(min, max))
};;;people ::= range(1, 100).map(x -> createPerson(12, 26));;;people = people.reduce({}, (acc, val) -> {
acc[val.name].total += val.age
acc[val.name].count += 1
acc
});;;people = people.map(x -> round(x.total / x.count, 2));;;table(people)
