# FOS help

## Structure of the source code

Source code is comprised of (non-mandatory) sections setup, video and graph and the differential equations we want to solve. The source code uses the UTF-8 encoding. The following rules apply for the order of the sections:

• Section setup has to be first.
• The order of sections graph and video is arbitrary, however they have to follow the setup section and be placed before the differential equations.
• Without the graph/video sections, plot containing all variables is created automatically.

### Section setup

Parameters in this section allow the user to specify the properties of computation.

setup {
// Parameters for the section setup
}


### Section graph

Parameters in this section allow the user to specify the properties of the created plots.

graph {
// Parameters for the section graph
}


### Section video

Parameters in this section allow the user to specify the properties of the created videos.

video {
// Parameters for the section video
}


## Equations

The user can use the following types of equations:

1. differential equations
• general structure
• y' = expr & cexpr; // the initial condition follows after the & character
• expr: operation addition, subtraction, multiplication, division, exponentiation, functions (sin, cos, tan, atan, ...)
• cexpr: expr, constants
• example
• y' = y &0;
2. algebraic equations
• example
• a = 5;

## Control flow - condition

The user can use the following notations for the condition statement:

### if

Simple condition. Can be used:

• as a block
• structure:
if (expr) {
// body of the condition
}

• examples:
• if(t < tmax/2) {
y' = sin(t) &0;
}

• together with an equation
• structure:
• t relop expr, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• expr relop t, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• expr relop t relop2 expr2, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• example:
• z = 1.5 if y<1.5;

### else

Condition with else branch. Can be used:

• as block
• structure:
if (expr) {
// body of the condition
} else {
// body of the condition
}

• example:
• if(t < tmax/2) {
y' = sin(t) &0;
} else {
y' = cos(t) &0;
}

• together with an equation
• structure:
• t relop expr, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• expr relop t, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• expr relop t relop2 expr2, kde
• relop: relation operator (<,<=,>=,>)
• expr: expression
• example:
• w = 2 if t<tmax/2 else 1;

### elif

Condition with else branch that also has an condition. Can be used:

• as block
• structure:
if (expr) {
// body of the condition
} elif(expr) {
// body of the condition
}

• example:
• if(t < tmax/2) {
y' = sin(t) &0;
elif(t < 3*tmax/4) {
y' = cos(t) &0;
}


## Overview of available parameters

### Parameters in the section setup

Names and values of all parameters in this section are case insensitive

### debug

Enables debug mode.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• debug = on;
• debug = false;
• debug = 1;

### digits

Number of displayed digits in the result.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 10

Example:

• digits = 20;

### doubleorder

Specifies the upper bound of the computation order. This bound is used to determine, whether the size of the integration step can be doubled (doubling of the size of the integration step is limited by the maxstep parameter). If $maxorder-minorder < 10$ holds, doubleorder is set to $max(0,maxorder-10)$

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: $minorder+(maxorder-minorder)/4$

### dt

Size of the integration step.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0.1

Example:

• dt = 0.01;

### eps

Accuracy of the calculation (see parameter test).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 1e-20

Example:

• eps = 1e-10;

### fixed

Ensures that the size of the integration step remains constant during calculation (halving of the integration step is only used during step-up.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• fixed = on;
• fixed = false;
• fixed = 1;

### graphs

Graphs are generated automatically from all variables, if the source code does not contain any graph sections.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: on

Example:

• graphs = on;
• graphs = false;
• graphs = 1;

### maxorder

Maximal order of hte method.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 64

Example:

• maxorder = 55;

### maxpower

For powers $x^n$, where $n<=maxpower$, powers are calculated normally. For values $n>maxpower$ the automatic transformation of the power calculation is performed.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: $10^9$

Example:

• maxpower = 1e7;

### maxstep

Maximal value of the integration step achieved automatically (setting this to 0 disables automatic increase).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: dt

Example:

• maxstep = 1e-2;

### method

Selects the integration method used for calculation.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: Taylor

Example:

• method = Euler;

### minorder

Minimal order of the method.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 10

Example:

• minorder = 5;

### precision (prec)

Number of bits of the significand. Evaluation is performed in the full range specified. Settings:

• $prec \leq 24: float$
• $prec \leq 53: double$
• $prec \leq 64: long double$
• $prec > 64: mpfr$

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 64

Example:

• prec = 80;

### range

Values large than than large wonÂ´t influence the values on the y axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 1e20

Example:

• range = 1e15;

### reach

Number of halvings of the integration step before the discrete event (for example if y > 1). Ensures step-up. Setting this to 0 disables the step-up.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 10

Example:

• reach = 12;

### test

Number of the Taylor series terms for the differential equation, that has to satisfy the following condition. If the condition is satisfied for all differential equations, the calculation in the current step ends. Evaluation of the condition is performed independently for every equation (each equation can have different order). General form of the condition: $\bigwedge_{i=1}^{test} |term_{N-i+1}| \leq eps$, where N is the current order.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 3

Example:

• test = 5;

### tmax

Maximal simulation time of the calculation..

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 1

Example:

• tmax = 10;

### tmin

Initial simulation time of the calculation.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0

Example:

• tmin = 1;

### zero

Values smaller than the accuracy eps are rounded to zero.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• zero = on;
• zero = false;
• zero = 1;

### Parameters in the section graph

Names and values of all parameters in this section are case sensitive

### background (bg)

Color of the background.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• background = blue;
• background = #CCC;
• background = #ABCDEF;

### colors

Colors of plots.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• colors = green;
• colors = #04f;
• colors = red, blue, #04f;

### domain (polar)

Polar coordinate system (the variable is used on the x axis).

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• domain = y;

### fill

Fills the are between the curve and the specified axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• fill = x1;
• fill = x1,y1;

### font

Sets font and the font size (used for the entire graph/video).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• font="times,12";

### foreground (fg)

Color of the foreground.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• foreground = blue;
• foreground = #CCC;
• foreground = #ABCDEF;

### format

Graph output format.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: png

Example:

• format = jpg;

### grid

Enables the grid.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• grid = on;
• grid = false;
• grid = 1;

### height

Height of the graph or video in pixels. It it is not specified, it is calculated automatically from the width to maintain the 4:3 aspect ratio.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 480

Example:

• height = 240;

### labels

Labels in the legend.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• labels = A, B;
• labels = "Abc"

### lalign

Legend alignment.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: left

Example:

• lalign=right;

### legend

Enables the legend.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• legend = on;
• legend = false;
• legend = 1;

### lfont

Sets font in the legend and the font size.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• font="times,12";

### linetypes (lt)

Types of lines. Does not work for JPG and GIF formats.

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• linetypes = solid, dashed;
• linetypes = dashdotted;

### log

Uses logarithmic scale on the specified axes.

The allowed values:

• Special type:
• x
• y
• xy

Example:

• log = x;

### lpos

Legend position.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• lpos=inside;

### marks

Displays marks in graph or video.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• marks = on;
• marks = false;
• marks = 1;

### marksizes (msizes)

Size of marks in the graph. Marks have to be enabled (marks=on).

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• msizes = 1, 2;
• marksizes = 3;

### name

Name of the graph or video.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• name = Graf1;

### pattern

Defines the fill style of the selected area. To select an area, use parameter fill. Negative values disable the border around the area.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• pattern = 2;

### show (select)

Specifies variables that are displayed.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+
• Pattern:
• every character matches itself, except %, ?, @ (jako *), [a-z], [^a-z]
• using the % character, the ordinary regular expressions (RE) can be used. Inside the RE, the (), {}, *, ?, +, [a-z], [^a-z] special characters are allowed (behaviour similar to the egrep utility).

Example:

• show = a, b;

### showorder (showord)

Displays the order of the method (only for method=Taylor;).

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• showorder = on;
• showord = false;
• showord = 1;

### square

Graph or video will have square dimension.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• square = on;
• square = false;
• square = 1;

### style

Style of graph or video.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: default

Example:

• style = tksl;

### thickness

Sets the thickess of lines.

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• thickness = cos(0);
• thickness = 1, 2;

### title

Name of graph or video.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• title = "My graph";

### values

Displays the values in the legend (legend has to be on - legend=on).

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• values = on;
• values = false;
• values = 1;

### width

Width of the graph or video in pixels. It it is not specified, it is calculated automatically from the height to maintain the 4:3 aspect ratio.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 640

Example:

• width = 320;

### xfmt

Format of the tick labels on the x axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• yfmt = "%2.0l";

### xlabel

Label of the x axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• xlabel = "Osa x";

### xlogbase (xbase)

Sets the x axis to have logarithmic scale with the specified base.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xlogbase = 2;
• xbase = 10;

### xmax

Maximal value on the x axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmax = 10.5;

### xmin

Minimal value on the x axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmin = 0.5;

### xmult

X-axis multiplication text (begins with the \times character).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• xmult = "10^{-11}";

### xmultx

Horizontal position of the xmult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmultx = 1.05;

### xmulty

Vertical position of the xmult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmulty = -0.06;

### xspace

Adds the multiple of the width from the left and the right (if the coordinate of the given side is not specified).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0

Example:

• xspace = 0.01;

### xtics

Spacing of the tics on the x axis. Can be specified as: - initial value, increment, end value; - initial value, increment; - increment.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ytics = 1,0.5,10;

### yfmt

Format of the tick labels on the y axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• yfmt = "%2.0l";

### ylabel

Label of the y axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• ylabel = "Osa y";

### ylogbase (ybase)

Sets the y axis to have logarithmic scale with the specified base.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ylogbase = 2;
• ybase = 10;

### ymax

Maximal value on the y axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymax = 10.5;

### ymin

Minimal value on the y axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymin = -0.5;

### ymult

Y-axis multiplication text (begins with the \times character).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• ymult = "10^{-11}";

### ymultx

Horizontal position of the ymult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymultx = -0.02;

### ymulty

Vertical position of the ymult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymulty = 1.02;

### yspace

Adds the multiple of the width from the upper and the lower side (if the coordinate of the given side is not specified).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0.01

Example:

• yspace = 0.01;

### ytics

Spacing of the tics on the y axis. Can be specified as: - initial value, increment, end value; - initial value, increment; - increment.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ytics = 1,0.5,10;

### Parameters in the section video

Names and values of all parameters in this section are case sensitive

### background (bg)

Color of the background.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• background = blue;
• background = #CCC;
• background = #ABCDEF;

### cairo

Use the png(cairo) GNUPLOT terminal.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: on

Example:

• cairo = on;
• cairo = false;
• cairo = 1;

### codec

Video codec used for compression. Name is not case sensitive.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: h264

Example:

• codec = MPEG1;
• codec = h263;

### colors

Colors of plots.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• colors = green;
• colors = #04f;
• colors = red, blue, #04f;

### columns (cols)

Number of columns in the joint video.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 1

Example:

• cols = 2;
• columns = 2;

### domain (polar)

Polar coordinate system (the variable is used on the x axis).

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• domain = y;

### duration (dur)

Duration of the video in seconds.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 10

Example:

• dur = 7;
• duration = 7;

### fill

Fills the are between the curve and the specified axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• fill = x1;
• fill = x1,y1;

### font

Sets font and the font size (used for the entire graph/video).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• font="times,12";

### foreground (fg)

Color of the foreground.

The allowed values:

• Color:
• named: red, green, blue, black, cyan, pink, magenta, yellow, ...

Example:

• foreground = blue;
• foreground = #CCC;
• foreground = #ABCDEF;

### format

Video output format.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: mp4

Example:

• format = avi;

### fps

Frame rate of the video.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 25

Example:

• fps = 20;

### grid

Enables the grid.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• grid = on;
• grid = false;
• grid = 1;

### height

Height of the graph or video in pixels. It it is not specified, it is calculated automatically from the width to maintain the 4:3 aspect ratio.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 480

Example:

• height = 240;

### join

Joins the selected plots into one video (if the videos with the specified names do not exist, new videos are automatically created using parameters from this section).

The allowed values:

• Identifier:  [a-zA-Z0-9_]+
• Pattern:
• every character matches itself, except %, ?, @ (jako *), [a-z], [^a-z]
• using the % character, the ordinary regular expressions (RE) can be used. Inside the RE, the (), {}, *, ?, +, [a-z], [^a-z] special characters are allowed (behaviour similar to the egrep utility).

Example:

• join = a, b;

### labels

Labels in the legend.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• labels = A, B;
• labels = "Abc"

### lalign

Legend alignment.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: left

Example:

• lalign=right;

### legend

Enables the legend.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• legend = on;
• legend = false;
• legend = 1;

### lfont

Sets font in the legend and the font size.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• font="times,12";

### linetypes (lt)

Types of lines. Does not work for JPG and GIF formats.

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• linetypes = solid, dashed;
• linetypes = dashdotted;

### log

Uses logarithmic scale on the specified axes.

The allowed values:

• Special type:
• x
• y
• xy

Example:

• log = x;

### lpos

Legend position.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• lpos=inside;

### marks

Displays marks in graph or video.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• marks = on;
• marks = false;
• marks = 1;

### marksizes (msizes)

Size of marks in the graph. Marks have to be enabled (marks=on).

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• msizes = 1, 2;
• marksizes = 3;

### name

Name of the graph or video.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Example:

• name = Graf1;

### pattern

Defines the fill style of the selected area. To select an area, use parameter fill. Negative values disable the border around the area.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• pattern = 2;

### quality (qual)

Video quality. Higher number means better quality (1 the worst, 9 the best).

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 5

Example:

• quality = 7;

### realtime (rt)

Uses sampling that matches the calculation speed (sample speed: speed/fps seconds).

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• realtime = on;
• realtime = false;
• realtime = 1;
• rt = on;

### show (select)

Specifies variables that are displayed.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+
• Pattern:
• every character matches itself, except %, ?, @ (jako *), [a-z], [^a-z]
• using the % character, the ordinary regular expressions (RE) can be used. Inside the RE, the (), {}, *, ?, +, [a-z], [^a-z] special characters are allowed (behaviour similar to the egrep utility).

Example:

• show = a, b;

### showorder (showord)

Displays the order of the method (only for method=Taylor;).

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• showorder = on;
• showord = false;
• showord = 1;

### speed

Speed of the video is increased/decreased (works only for realtime=on).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 1

Example:

• speed = 1.5;
• speed = 2;

### square

Graph or video will have square dimension.

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Default value: off

Example:

• square = on;
• square = false;
• square = 1;

### style

Style of graph or video.

The allowed values:

• Identifier:  [a-zA-Z0-9_]+

Default value: default

Example:

• style = tksl;

### thickness

Sets the thickess of lines.

The allowed values:

• Integer number:  [+-]?[0-9]+

Example:

• thickness = cos(0);
• thickness = 1, 2;

### title

Name of graph or video.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• title = "My graph";

### values

Displays the values in the legend (legend has to be on - legend=on).

The allowed values:

• Logical value:
• true/false
• on/off
• 1/0

Example:

• values = on;
• values = false;
• values = 1;

### width

Width of the graph or video in pixels. It it is not specified, it is calculated automatically from the height to maintain the 4:3 aspect ratio.

The allowed values:

• Integer number:  [+-]?[0-9]+

Default value: 640

Example:

• width = 320;

### xfmt

Format of the tick labels on the x axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• yfmt = "%2.0l";

### xlabel

Label of the x axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• xlabel = "Osa x";

### xlogbase (xbase)

Sets the x axis to have logarithmic scale with the specified base.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xlogbase = 2;
• xbase = 10;

### xmax

Maximal value on the x axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmax = 10.5;

### xmin

Minimal value on the x axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmin = 0.5;

### xmult

X-axis multiplication text (begins with the \times character).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• xmult = "10^{-11}";

### xmultx

Horizontal position of the xmult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmultx = 1.05;

### xmulty

Vertical position of the xmult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• xmulty = -0.06;

### xspace

Adds the multiple of the width from the left and the right (if the coordinate of the given side is not specified).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0

Example:

• xspace = 0.01;

### xtics

Spacing of the tics on the x axis. Can be specified as: - initial value, increment, end value; - initial value, increment; - increment.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ytics = 1,0.5,10;

### yfmt

Format of the tick labels on the y axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• yfmt = "%2.0l";

### ylabel

Label of the y axis.

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"
• Identifier:  [a-zA-Z0-9_]+

Example:

• ylabel = "Osa y";

### ylogbase (ybase)

Sets the y axis to have logarithmic scale with the specified base.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ylogbase = 2;
• ybase = 10;

### ymax

Maximal value on the y axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymax = 10.5;

### ymin

Minimal value on the y axis.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymin = -0.5;

### ymult

Y-axis multiplication text (begins with the \times character).

The allowed values:

• String in parenthesis:  "([^"\\]*(\\.)*)*"

Example:

• ymult = "10^{-11}";

### ymultx

Horizontal position of the ymult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymultx = -0.02;

### ymulty

Vertical position of the ymult multiplication text.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ymulty = 1.02;

### yspace

Adds the multiple of the width from the upper and the lower side (if the coordinate of the given side is not specified).

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Default value: 0.01

Example:

• yspace = 0.01;

### ytics

Spacing of the tics on the y axis. Can be specified as: - initial value, increment, end value; - initial value, increment; - increment.

The allowed values:

• Floating point number:  [+-]?[0-9]+(\.[0-9]+)?([eE][+-]?[0-9]+)?

Example:

• ytics = 1,0.5,10;

### Keywords - section setup

In the section , the following keywords can be used:

• debug
• digits
• doubleorder
• dt
• eps
• fixed
• graphs
• maxorder
• maxpower
• maxstep
• method
• minorder
• precision
• range
• reach
• test
• tmax
• tmin
• zero