Other Update Methods

Using squap.show() with squap.on_refresh() is not the only way to implement updating plots. Each of the following has their uses, so before starting a new program decide which method fits best, or combine several.

Using show_window

Instead of using squap.show() with squap.on_refresh(), it is also possible to use squap.show_window() with squap.refresh(). This allows you to update the code inside a loop instead of with functions like update in the previous examples. This method might be a little less robust, so for more complex simulations it is usually better practice to use squap.show().

import squap
import numpy as np


x = np.linspace(0, 2*np.pi, 100)

curve = squap.scatter(c="r")

squap.set_xlim(0, 2 * np.pi)
squap.set_ylim(-1, 1)
squap.show_window()

t = 0
dt = 0.005

while squap.is_alive():
    curve.set_data(x, np.sin(x+t))
    t += dt
    squap.refresh(call_update_funcs=True)

The loop repeats while squap.is_alive() returns True. This makes sure the loop stops when the window is closed.

Using Box.bind

When there is no time dependence but there are parameters which are controlled by input boxes, it is more useful to make use of Box.bind. A function is then bound to a specific box, meaning it only runs when the value of the box changes.

import squap
from squap import var
import numpy as np


def update():
    curve_1.set_data(var.x, np.cos(var.x + var.b))
    curve_2.set_data(var.x, np.sin(var.x + var.a))


def update_num_points():
    var.x = np.linspace(0, 2*np.pi, var.N_x)
    update()


update_boxes = [
    squap.add_slider("a", 0, 0, 2*np.pi),
    squap.add_inputbox("b", 0)
]
for box in update_boxes:
    box.bind(update)

squap.add_inputbox("N_x", 50, type_func=int).bind(update_num_points)

curve_1 = squap.scatter(c="r")
curve_2 = squap.plot()

update_num_points()

squap.set_xlim(0, 2 * np.pi)
squap.set_ylim(-1, 1)
squap.on_refresh(update)
squap.show()

Using A Button

When calculating the next frame is especially slow, consider only updating on the press of a button:

import squap
from squap import var
import numpy as np
import time


def update():
    time.sleep(1)           # calculate lots of stuff
    curve.set_data(x, np.sin(x + var.a))


x = np.linspace(0, 2*np.pi, 100)
squap.add_slider("a", 0, 0, 2*np.pi),
squap.add_button("update", update)

curve = squap.scatter(c="r")

squap.set_xlim(0, 2 * np.pi)
squap.set_ylim(-1, 1)
squap.show()