User manual

Table Of Contents
Publication No. 980935 Rev. M 3152B User Manual
Astronics Test Systems ArbConnection 4-49
Writing Equations
The Equation Editor lets you process mathematical expressions
and convert them into waveform coordinates.
As you probably
already know, waveforms are made of vertical samples. The
number of samples on your waveform is determined by the
wavelength parameter. For example, if you have 1024 horizontal
points, your equation will be computed along 1024 points as a
function of the vertical scale. Each vertical sample is computed
separately and placed along the horizontal axis. The points are
graphically connected to form a uniform and continuous waveform
shape however, if you zoom in on a waveform line, you’ll see that
the points are connected like a staircase. In reality, the 3152B
generates its waveforms exactly as shown on the screen but, if the
waveform has many horizontal points, the steps get smaller and
harder to see without magnification.
Equations are always
computed as a function of the vertical
(Amplitude) axis therefore the left side of your equation will always
look as Amplitude(p)
=, where “p” is the equation variables in units
of waveform points. You can write equations with up to 256
characters. If the
equation is too long to fit in the visible field, parts
to the left or right will scroll off the ends.
Equation
Convention
s
Equations are written in conventional mathematical notation. You
may only enter the right part of the equation. The only limitatio
n is
that the equation must be of a single variable that is directly related
to the current horizontal axis setting. Case is not important and
spaces are ignored. Numbers are entered in scientific notation. All
calculations are done with double precision.
For trigonometric
functions, all angles are expressed in radians.
A number of constants are provided: e, which is the base of the
natural logarithm; pi, which is the circumference of a unit-diameter
circle; per, which equals the programmed horizontal rang
e; f, which
equals 1 /per; omg, which equals 2 * pi * f, and number
s in the
range of -1E^20 to 1E^20.
There are three classes of precedence: ^ (raise to power) has the
highest precedence; * (multiply) and / (divide) come second; + and -
have the lowest pre
cedence. Parentheses may be used to change
the order of precedence. The following table summarizes the
mathematical expressions and their respective abbreviated
commands that can be used with Equation Editor.
Equation Editor Operands
^ Raise to the power
* Multiply
/ Divide
+ Add
- Subtract
( ) Parentheses
e Base of natural Logarithm