Home Accessibility Courses Twitter The Mouth Facebook Resources Site Map About Us Contact
For 2021 - online Python 3 training - see ((here)).

Our plans were to retire in summer 2020 and see the world, but Coronavirus has lead us into a lot of lockdown programming in Python 3 and PHP 7.
We can now offer tailored online training - small groups, real tutors - works really well for groups of 4 to 14 delegates. Anywhere in the world; course language English.

Please ask about private 'maintenance' training for Python 2, Tcl, Perl, PHP, Lua, etc.
Maths functions and random number generators
Other Standard Library features. example from a Well House Consultants training course
More on Other Standard Library features. [link]
Source code: mathfuncs Module: U112

Lua has a rich range of maths functions which are
illustrated here

Random generators can produce integers or floats,
and can be seeded to produce an everyvarying
sequence, or the same sequence each time (for testing)

-- Returns the absolute value of x.
x = -2.6
print ("Starting with " .. x)
x = math.abs (x)
print (x)

-- Returns the cosine of x (assumed to be in radians).
x = math.cos (x)
print (x)
-- Returns the arc cosine of x (in radians).
x = math.acos (x)
print (x)

--[[ Returns the arc tangent of y/x (in radians), and uses
the signs of both parameters to find the quadrant of the result. ]]

y = 17.0
x = math.atan2 (y, x)
print (x)

-- Returns the smallest integer larger than or equal to x.
x = math.ceil (x)
print (x .. " ceiling ...")

-- Returns the hyperbolic cosine of x.
x = math.cosh (x)
print (x)

-- Returns the angle x (given in radians) in degrees.
-- math.rad for reverse
x = math.deg (x)
print (x)
x = math.rad(x)
print (x)

-- Returns the value ex.
x = math.exp (x)
print (x)

-- Returns the largest integer smaller than or equal to x.
x = math.floor (x)
print (x .. " floor ...")

-- Returns the remainder of the division of x by y.
x = math.fmod (x, y)
print (x)

-- Returns the natural logarithm of x.
x = math.log (x)
print (x)

-- Returns the base-10 logarithm of x.
x = math.log10 (x)
print (x)

-- Returns the square root of x.
x = math.sqrt (x)
print (x)

-- The value of pi.
print (math.pi)

-- x to power y. (You can also use the expression x^y to compute this value.)
x = math.pow (x, y)
print (x .. " power ...")

print ("\nrandom reals")
math.randomseed (x) -- to give same sequence each time
dums = {}
ost = ""
for k=1,10 do
        dums[k] = math.random()
        ost = ost .. " / " .. dums[k]
print (ost)

print ("\nrandom integers")
math.randomseed(os.time()) -- sequence changes every second
dums = {}
ost = ""
for k=1,10 do
        dums[k] = math.random(101,152)
        ost = ost .. " / " .. dums[k]
print (ost)

--[[ ------------------- Sample Output
[trainee@easterton u112]$ lua mathfuncs
Starting with -2.6
2 ceiling ...
43 floor ...
0.0082546681657717 power ...

random reals
 / 0.84018771715471 / 0.39438292681909 / 0.78309922375861 / 0.79844003347607 / 0.91164735793678 / 0.19755136929338 / 0.33522275571489 / 0.7682295948119 / 0.27777471080319 / 0.55396995579543

random integers
 / 122 / 128 / 109 / 114 / 136 / 148 / 134 / 129 / 102 / 101
[trainee@easterton u112]$


Learn about this subject
This module and example are covered on the following public courses:
 * Learning to program in Lua
 * Lua Programming
 * Lua Programming
Also available on on site courses for larger groups

Books covering this topic
Yes. We have over 700 books in our library. Books covering Lua are listed here and when you've selected a relevant book we'll link you on to Amazon to order.

Other Examples
This example comes from our "Other Standard Library features." training module. You'll find a description of the topic and some other closely related examples on the "Other Standard Library features." module index page.

Full description of the source code
You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.

Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.

Other resources
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.

Web site author
This web site is written and maintained by Well House Consultants.

Purpose of this website
This is a sample program, class demonstration or answer from a training course. It's main purpose is to provide an after-course service to customers who have attended our public private or on site courses, but the examples are made generally available under conditions described below.

Conditions of use
Past attendees on our training courses are welcome to use individual examples in the course of their programming, but must check the examples they use to ensure that they are suitable for their job. Remember that some of our examples show you how not to do things - check in your notes. Well House Consultants take no responsibility for the suitability of these example programs to customer's needs.

This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.

Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2022: 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
PH: 01144 1225 708225 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho

PAGE: http://www.wellho.net/resources/ex.php • PAGE BUILT: Sun Oct 11 14:50:09 2020 • BUILD SYSTEM: JelliaJamb