# Difference between revisions of "TAChart documentation"

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Also, by setting <code>Active</code>=true, <code>Pen.Style=psClear</code> and | Also, by setting <code>Active</code>=true, <code>Pen.Style=psClear</code> and | ||

− | <code>UseBounds=true</code> and appropriate <code>AxisIndexX</code>, it becomes | + | <code>UseBounds=true</code> and appropriate <code>AxisIndexX</code>, it becomes "axis extender", |

making sure that given <code>Position</code> will always by included in the axis range. | making sure that given <code>Position</code> will always by included in the axis range. | ||

=== Basic series === | === Basic series === | ||

− | Basic series are | + | Basic series are mos often used, and include [[#Line series|line]], [[#Bar series|bar]] and [[#Area series|area]] series. |

All basic series can be "stacked" by using [[#Multi-valued sources|multi-valued source]]. | All basic series can be "stacked" by using [[#Multi-valued sources|multi-valued source]]. | ||

Also, all basic series fully support rotation and 3-D drawing. | Also, all basic series fully support rotation and 3-D drawing. | ||

Line 32: | Line 32: | ||

==== Line series ==== | ==== Line series ==== | ||

− | <code>TLineSeries</code> can be used to draw | + | <code>TLineSeries</code> can be used to draw give set of points, |

optionally marking them with shapes and connecting with lines. | optionally marking them with shapes and connecting with lines. | ||

− | You can get | + | You can get "stepped" look by setting <code>LineType</code> property to <code>ltStepXY</code> or <code>ltStepYX</code>. |

===== Fast lines ===== | ===== Fast lines ===== | ||

Line 41: | Line 41: | ||

Some charting packages include special "fast line" series to quickly draw | Some charting packages include special "fast line" series to quickly draw | ||

line series from extremely large datasets (10000+ points). | line series from extremely large datasets (10000+ points). | ||

− | Instead, TAChart contains optimized | + | Instead, TAChart contains optimized fast path inside standard line series code, |

achieving comparable drawing speed. | achieving comparable drawing speed. | ||

− | Line series will | + | Line series will draw very fast if all of the following are true: |

− | * There | + | * There is no marks. |

− | * There | + | * There is no pointers. |

* <code>LineType</code> is not <code>ltFromOrigin</code>. | * <code>LineType</code> is not <code>ltFromOrigin</code>. | ||

Line 70: | Line 70: | ||

or infinitely down (if <code>UseZeroLevel=false</code>). | or infinitely down (if <code>UseZeroLevel=false</code>). | ||

− | You can get | + | You can get "stepped" look by setting <code>ConnectType</code> property. |

=== Multi-value series === | === Multi-value series === | ||

Line 79: | Line 79: | ||

==== Bubble series ==== | ==== Bubble series ==== | ||

− | <code>TBubbleSeries</code> represent data as circles of variable radius centered | + | <code>TBubbleSeries</code> represent data as a circles of variable radius centered at data points. |

− | This series | + | This series require source with <code>YCount</code> of at least 2, |

− | and | + | and use first additional Y value as radius. |

==== Box-and-whiskers series ==== | ==== Box-and-whiskers series ==== | ||

Line 87: | Line 87: | ||

<code>TBoxAndWhiskerSeries</code> represents data as rectangles with a medium line and | <code>TBoxAndWhiskerSeries</code> represents data as rectangles with a medium line and | ||

two T-like shape protruding in both directions. | two T-like shape protruding in both directions. | ||

− | Although in statistics [[Wikipedia:Box_plot|box-and whiskers plot]] is supposed to be based | + | Although in statistics [[Wikipedia:Box_plot|box-and whiskers plot]] is supposed to be based in specific |

− | data quartiles, TAChart does not enforce this, allowing | + | data quartiles, TAChart does not enforce this, allowing user to draw arbitrary plots. |

With some effort, box-and whiskers series may be used to represent other charts | With some effort, box-and whiskers series may be used to represent other charts | ||

Line 94: | Line 94: | ||

[[Wikipedia:Gantt_chart|Gantt diagram]] or [[Wikipedia:Candlestick_chart|Candlestick chart]]. | [[Wikipedia:Gantt_chart|Gantt diagram]] or [[Wikipedia:Candlestick_chart|Candlestick chart]]. | ||

− | This series | + | This series require source with <code>YCount</code> of at least 5, and use Y values as follows: |

{| | {| | ||

!Index!!Usage | !Index!!Usage | ||

Line 112: | Line 112: | ||

==== Open-high-low-close series ==== | ==== Open-high-low-close series ==== | ||

− | <code>TOpenHighLowCloseSeries</code> represent data as vertical lines with two ticks, | + | <code>TOpenHighLowCloseSeries</code> represent data as a vertical lines with two ticks, |

as described [[Wikipedia:Open-high-low-close_chart|here]]. | as described [[Wikipedia:Open-high-low-close_chart|here]]. | ||

− | It usually requires <code>YCount</code> of at least 4, and | + | It usually requires <code>YCount</code> of at least 4, and use Y values as follows: |

{| | {| | ||

!Property!!Default!!Usage | !Property!!Default!!Usage | ||

Line 134: | Line 134: | ||

=== Radial series === | === Radial series === | ||

− | You can see | + | Radial series ignore axis transformations. |

+ | You can see examples of radial series in "radial" demo. | ||

==== Pie series ==== | ==== Pie series ==== | ||

+ | <code>TPieSeries</code> draws pie charts. | ||

+ | |||

+ | For each data point, pie series interprets Y value as a relative size of the slice, | ||

+ | and X value as a distance of splice from the center of the pie (only if <code>Exploded</code> property is true). | ||

+ | Slice colors can be set in data items, or taken from the hard-coded list. | ||

+ | |||

+ | Pie radius can be either set manually by <code>FixedRadius</code> property, | ||

+ | or calculated automatically so that the whole series, including all labels, exactly fits the parent chart. | ||

+ | |||

+ | There are several options for label positioning, controlled by <code>MarkPositions</code> property: | ||

+ | * <code>pmpAround</code> -- marks are drawn outside the pie, on the continuation or radius vector for each slice | ||

+ | * <code>pmpInside</code> -- marks are drawn inside each slice | ||

+ | * <code>pmpLeftRight</code> -- marks are drawn directly to the left or to the right of slice | ||

+ | |||

+ | If <code>RotateLabels</code> is true, each label is additionally rotated so that | ||

+ | (if <code>LabelFont.Orientation=0</code>) it is parallel to the radius vector of its slice. | ||

==== Polar series ==== | ==== Polar series ==== | ||

− | <code>TPolarSeries</code> | + | <code>TPolarSeries</code> represent data as points in [[Wikipedia:Polar_coordinate_system|polar coordinates]]. |

The origin of the polar coordinate system is defined in graph coordinates by <code>OriginX</code> and <code>OriginY</code> | The origin of the polar coordinate system is defined in graph coordinates by <code>OriginX</code> and <code>OriginY</code> | ||

properties. | properties. | ||

− | For each data point, X value is interpreted as angle in radians and Y value as a distance from the center. | + | For each data point, X value is interpreted as an angle in radians and Y value -- as a distance from the center. |

=== User-drawn series === | === User-drawn series === | ||

+ | |||

+ | Provides <code>OnDraw</code> and <code>OnGetBounds</code> events to allow arbitrary custom drawing on the TChart. | ||

+ | Note that using <code>TChart.Canvas</code> directly is highly discouraged an will often not as expected. | ||

=== Functional series === | === Functional series === | ||

+ | |||

+ | Functional series are recommended way to draw functional plots as opposed to, for example, | ||

+ | pre-calculating function data and using [[#Line seres|line series]]. | ||

+ | They provide scale-independent controls of smoothness vs drawing speed. | ||

+ | |||

+ | You can see examples of functional series in "func" demo. | ||

+ | |||

+ | ==== Function series ==== | ||

+ | |||

+ | <code>TFuncSeries</code> represents a one-dimensional function defined by <code>OnCalculate</code> event as a line. | ||

+ | |||

+ | The function is calculated for each <code>Step</code> pixels of the image, so you can | ||

+ | use this property to increase "smoothnes" or drawing speed. | ||

+ | |||

+ | <code>DomainExclusions</code> property allows to exclude some intervals from the function domain. | ||

+ | Function series correctly draws discontinuity points set by <code>DomainExclusions</code>. | ||

+ | Currently, <code>DomainExclusions</code> can only be set at run-time. | ||

+ | |||

+ | ==== B-spline series ==== | ||

+ | |||

+ | <code>TBSplineSeries</code> draws [[Wikipedia:B-spline|B-spline]] of given <code>Dergee</code> using [[Wikipedia:De_Boor's_algorithm|De Boor's algorithm]]. | ||

+ | |||

+ | Spline segments shorter then <code>Step</code> pixels are represented by straight lines. | ||

+ | |||

+ | ==== Cubic spline series ==== | ||

+ | |||

+ | <code>TCubicSplineSeries</code> draws [[Wikipedia:Spline_interpolation:: cubic spline]] using standard | ||

+ | Numlib package from the FPC. | ||

+ | |||

+ | The spline function is calculated for each <code>Step</code> pixels of the image, so you can | ||

+ | use this property to increase "smoothnes" or drawing speed. | ||

+ | |||

+ | Data source must contain at least 4 points and have strictly increasing X coordinate. | ||

+ | |||

+ | If there are too few points, and <code>csoDrawFewPoints</code> option is set, | ||

+ | line will be drawn instead of spline using <code>BadDataPen</code>. | ||

+ | |||

+ | If X values are unordered and <code>csoDrawUnorderedX</code> option is set, | ||

+ | spline will be drawn ignoring offending points using <code>BadDataPen</code>. | ||

+ | |||

+ | <code>csoExtrapolateLeft</code> and <code>csoExtrapolateRight</code> options enable natural | ||

+ | extrapolation to the left and to the right correspondingly. | ||

+ | |||

+ | ==== Color map series ==== | ||

+ | |||

+ | <code>TColorMapSeries</code> represent 2-dimensional function defined by <code>OnCalculate</code> event | ||

+ | as a field of pixels, with color depending on function value. | ||

+ | |||

+ | The field is drawn as a set of rectangles of size <code>StepX</code> by <code>StepY</code> pixels. | ||

+ | The function is called once for each rectangle. | ||

+ | |||

+ | Color values are defined by <code>ColorSource</code>, which must be sorted. | ||

+ | For each data point is interpreted as having X value correspond to Color value. | ||

+ | If the actual value falls between color levels, it can be either linearly interpolated | ||

+ | (if <code>Interpolate=true</code>) or rounded down to the nearest level. | ||

+ | |||

+ | When <code>Legend.Multiplicity=lmPoint</code>, color map series will display | ||

+ | color levels in the [[#Legend|legend]. | ||

== Sources == | == Sources == |

## Revision as of 11:27, 29 July 2011

│
**English (en)** │
**русский (ru)** │
**українська (uk)** │
**中文（中国大陆） (zh_CN)** │

## Contents

## Overview

TAChart is a package for drawing graphs, charts and other diagrams. It is comparable in features, but not specifically compatible, with Delphi TeeChart package. One substantial difference is that some features (e.g. data sources and axis transformations) are implemented via separate components instead of just properties. This leads to increased flexibility and opportunity for code re-use, but at the cost of some additional API complexity.

## Series

Series are the central part of TAChart. Most of the series represent data taken from data sources in graphical ways, such as lines or bars.

### Constant line series

This is the simplest series type, representing "infinite" vertical or horizontal line. It can be used as "central axis" in function graphs or as a draggable marker.

Also, by setting `Active`

=true, `Pen.Style=psClear`

and
`UseBounds=true`

and appropriate `AxisIndexX`

, it becomes "axis extender",
making sure that given `Position`

will always by included in the axis range.

### Basic series

Basic series are mos often used, and include line, bar and area series. All basic series can be "stacked" by using multi-valued source. Also, all basic series fully support rotation and 3-D drawing.

#### Line series

`TLineSeries`

can be used to draw give set of points,
optionally marking them with shapes and connecting with lines.

You can get "stepped" look by setting `LineType`

property to `ltStepXY`

or `ltStepYX`

.

##### Fast lines

Some charting packages include special "fast line" series to quickly draw line series from extremely large datasets (10000+ points). Instead, TAChart contains optimized fast path inside standard line series code, achieving comparable drawing speed. Line series will draw very fast if all of the following are true:

- There is no marks.
- There is no pointers.
`LineType`

is not`ltFromOrigin`

.

Some operating systems/widgetsets may additionally require that
`LinePen.Style=psSolid`

and `LinePen.Width=1`

.

Additional speedups will be available if `Source.Sorted=true`

.

You can measure line speed drawing on your platform with the "line" demo.

#### Bar series

`TBarSeries`

represents data as a set or bars, extending from `ZeroLevel`

to data points.

You can control bar width with `BarWidthPercent`

property. Note that the it is measured relative to the
neighboring bars. If the X values are not equidistant, bars will have varying width.
To prevent that, set `BarWidthStyle=bwPercentMin`

.

You can draw multiple bar series side-by-side by using `BarOffsetPercent`

property.

#### Area series

`TAreaSeries`

represents data as a polygon extending from the data points to either `ZeroLevel`

line
or infinitely down (if `UseZeroLevel=false`

).

You can get "stepped" look by setting `ConnectType`

property.

### Multi-value series

Multi-value series require multi-valued data source, and use additional Y values as extra parameters to draw complex shapes.

#### Bubble series

`TBubbleSeries`

represent data as a circles of variable radius centered at data points.
This series require source with `YCount`

of at least 2,
and use first additional Y value as radius.

#### Box-and-whiskers series

`TBoxAndWhiskerSeries`

represents data as rectangles with a medium line and
two T-like shape protruding in both directions.
Although in statistics box-and whiskers plot is supposed to be based in specific
data quartiles, TAChart does not enforce this, allowing user to draw arbitrary plots.

With some effort, box-and whiskers series may be used to represent other charts different in meaning, but similar in appearance, such as Gantt diagram or Candlestick chart.

This series require source with `YCount`

of at least 5, and use Y values as follows:

Index | Usage |
---|---|

0 | Lower whisker |

1 | Lower box bound |

2 | Medium line |

3 | Upper box bound |

4 | Upper whisker |

#### Open-high-low-close series

`TOpenHighLowCloseSeries`

represent data as a vertical lines with two ticks,
as described here.

It usually requires `YCount`

of at least 4, and use Y values as follows:

Property | Default | Usage |
---|---|---|

YIndexLow | 0 | Lower point of line |

YIndexOpen | 1 | Left-facing tick position |

YIndexClose | 2 | Right-facing tick position |

YIndexHigh | 3 | Upper point of line |

Note that although Y values are supposed to be ordered ascending along the table above, the series does not enforce this and will draw any supplied data.

### Radial series

Radial series ignore axis transformations. You can see examples of radial series in "radial" demo.

#### Pie series

`TPieSeries`

draws pie charts.

For each data point, pie series interprets Y value as a relative size of the slice,
and X value as a distance of splice from the center of the pie (only if `Exploded`

property is true).
Slice colors can be set in data items, or taken from the hard-coded list.

Pie radius can be either set manually by `FixedRadius`

property,
or calculated automatically so that the whole series, including all labels, exactly fits the parent chart.

There are several options for label positioning, controlled by `MarkPositions`

property:

`pmpAround`

-- marks are drawn outside the pie, on the continuation or radius vector for each slice`pmpInside`

-- marks are drawn inside each slice`pmpLeftRight`

-- marks are drawn directly to the left or to the right of slice

If `RotateLabels`

is true, each label is additionally rotated so that
(if `LabelFont.Orientation=0`

) it is parallel to the radius vector of its slice.

#### Polar series

`TPolarSeries`

represent data as points in polar coordinates.

The origin of the polar coordinate system is defined in graph coordinates by `OriginX`

and `OriginY`

properties.

For each data point, X value is interpreted as an angle in radians and Y value -- as a distance from the center.

### User-drawn series

Provides `OnDraw`

and `OnGetBounds`

events to allow arbitrary custom drawing on the TChart.
Note that using `TChart.Canvas`

directly is highly discouraged an will often not as expected.

### Functional series

Functional series are recommended way to draw functional plots as opposed to, for example, pre-calculating function data and using line series. They provide scale-independent controls of smoothness vs drawing speed.

You can see examples of functional series in "func" demo.

#### Function series

`TFuncSeries`

represents a one-dimensional function defined by `OnCalculate`

event as a line.

The function is calculated for each `Step`

pixels of the image, so you can
use this property to increase "smoothnes" or drawing speed.

`DomainExclusions`

property allows to exclude some intervals from the function domain.
Function series correctly draws discontinuity points set by `DomainExclusions`

.
Currently, `DomainExclusions`

can only be set at run-time.

#### B-spline series

`TBSplineSeries`

draws B-spline of given `Dergee`

using De Boor's algorithm.

Spline segments shorter then `Step`

pixels are represented by straight lines.

#### Cubic spline series

`TCubicSplineSeries`

draws Wikipedia:Spline_interpolation:: cubic spline using standard
Numlib package from the FPC.

The spline function is calculated for each `Step`

pixels of the image, so you can
use this property to increase "smoothnes" or drawing speed.

Data source must contain at least 4 points and have strictly increasing X coordinate.

If there are too few points, and `csoDrawFewPoints`

option is set,
line will be drawn instead of spline using `BadDataPen`

.

If X values are unordered and `csoDrawUnorderedX`

option is set,
spline will be drawn ignoring offending points using `BadDataPen`

.

`csoExtrapolateLeft`

and `csoExtrapolateRight`

options enable natural
extrapolation to the left and to the right correspondingly.

#### Color map series

`TColorMapSeries`

represent 2-dimensional function defined by `OnCalculate`

event
as a field of pixels, with color depending on function value.

The field is drawn as a set of rectangles of size `StepX`

by `StepY`

pixels.
The function is called once for each rectangle.

Color values are defined by `ColorSource`

, which must be sorted.
For each data point is interpreted as having X value correspond to Color value.
If the actual value falls between color levels, it can be either linearly interpolated
(if `Interpolate=true`

) or rounded down to the nearest level.

When `Legend.Multiplicity=lmPoint`

, color map series will display
color levels in the [[#Legend|legend].

## Sources

Data can get into a chart from various sources.
They are implemented as a set of components derived from `TCustomChartSource`

.

To assign a source to a series, you can set the `Source`

property.
If the property is left unassigned, the series will use its own built-in list source.
Methods like `AddXY`

are delegated to the current series source.
Note that the list source is the only editable source, so after you assign,
for example, a random chart source to the series, a call to `AddXY`

will raise an exception.

Each data item has the following fields: X, Y, YList, Color, Text.

### Sorted sources

If it is known that X values of the source are ascending,
some additional optimizations like binary search become possible.
So all sources have `IsSorted`

property which helps determine that.

### Multi-valued sources

Sources can contain multiple Y values for each X value.
These values are stored in the `YList`

field of the source data item.
The number of Y values is determined by the `YCount`

property.
Note that the first Y value is stored in Y field anyway, so `YCount`

= 3
means that values are stored in `Y`

, `YList[0]`

and `YList[1]`

.

Additional values may be used by various series -- for example, stacked bars or bubble charts.

### List source

`TListChartSource`

is a basic chart source, storing chart data inside itself.
As such, you can use `Add`

and `Delete`

function to change source data.

The source also has `DataPoints`

property to allow setting data at design time.
This property is a TStringList, with each line representing a data point.
Line consists of X, Y, optional YList, Color and Text values separated by | (vertical bar) character.
Note that `DataPoints`

property is designed primarily for sample and demo code.
It is very inefficient, and you should not use it to add data points from the code.

You can control X value sorting by setting the `Sorted`

property.
Note when `Sorted`

is set to true, list source sorts the data and keeps it sorted
after insertion of new points. If inserted points are not sorted, this may result
in quadratic running time.
To avoid this, you should so either set `Sorted`

to true only after insertion,
or pre-sort your data.

### Random source

`TRandomChartSource`

source generates random data in the given range and is intended mostly to use in demos.
You can also use it as design-time replacement for you actual data source.
This will let you see and change the look of your chart without having to run the application.

Each random source uses its own independent random number generator to guarantee stability of its values.

### User-defined source

This source may be used if you already have your data in memory, but in a format different from the data items used in TAChart. Using user-defined source to access your data directly instead of first moving it all into a list source may (or may not) be beneficial for speed.

You can of course also use a user-defined source to generate, filter or modify data.

Note that if the `Sorted`

property is set to true, it is the responsibility
of the event handler to provide actually sorted data.

### Database source

`TDbChartSource`

takes data directly from a database.
It is contained in a separate unit to avoid introducing a db-aware component dependency
into every project using TAChart.

The following properties contain database field names for data item fields:

Property | Access method |
---|---|

`FieldX` |
AsFloat |

`FieldY` |
AsFloat |

`FieldColor` |
AsInteger |

`FieldText` |
AsString |

If `FieldX`

property is empty, RecNo is used instead.

To get multi-valued source, set `FieldY`

property to a comma-separated list of field names.
Note that `YCount`

will be set automatically -- trying to set it by hand will raise an exception.

### Calculated source

`TCalculatedChartSource`

is the source used for manipulating data taken from the
`Origin`

source.
This source performs transformations in the following order:

- Y reordering -- Y values of multi-valued source can be duplicated, removed or exchanged according to
`ReorderYList`

property, which is a comma-separated list of original Y value indexes. Step skipped if`ReorderYList`

is empty. - Accumulation -- replaces each item's Y values by some function (for example, sum or average) of the last
`AccumulationRange`

items. Step skipped if the`AccumulationMethod`

property is`camNone`

. - Percentage -- replace each Y value by the percentage of total of all Y values for that item. Useful for drawing "stacked percentage" bar and area charts. Step skipped if the
`Percentage`

property is false.

### Efficiency notes

Primary data source API allows random access. Nevertheless, many sources, in particular random, database and calculated, may exhibit quadratic or worse behavior if actually accessed randomly. TAChart itself takes care to only use sequential access (although it may require several passes). Sources optimize sequential access by using internal state. User code should be careful not to reset this state during chart drawing from event handlers or custom series code.

A notable exception is the list source, which is guaranteed to provide fast random access.
It may be used to cache slow sources with the help of `CopyForm`

procedure.

## Coordinates and axises

TAChart uses three coordinate systems:

*Axis coordinates*(known in some other applications as object coordinates) -- this is the "raw" coordinate values obtained from the data. As the name implies, axis coordinates are interpreted in terms of specific axis -- the same coordinate value may have different meaning depending on the axis it is applied to.*Graph coordinates*(aka world coordinates) are converted from the axis coordinates using axis transformation, such as logarithmic scale. Graph coordinates are common for all objects in the chart.*Image coordinates*(aka screen coordinates) are converted from graph coordinates based on the chart viewport. This transformation is always linear and can be influenced by chart tools such as zooming and panning.

You can add or remove an arbitrary number of axises by editing `AxisList`

property.
By default, chart have two axises: one horizontal and one vertical.
They are accessible via `BottomAxis`

and `LeftAxis`

properties.
Note that those properties are aliases to `AxisList[0]`

and `AxisList[1]`

,
so if you remove those default axises, accessing `BottomAxis`

and `LeftAxis`

will return nil.

### Axis transformations

Axis transformations are grouped in the `TChartAxisTransformations`

component.
It contains a list of transformations which are applied in the order given.
(For example, performing scale before and after logarithm will yield different results).

For transformations to have an effect, you should:

- Make sure
`Enabled`

property is true for all transformations. - Assign transformations component to
`Transformations`

property of at least one axis. - Assign
`AxisIndexX`

and/or`AxisIndexY`

properties of the series to the appropriate axis index.

Note that by default, `AxisIndexX`

and `AxisIndexY`

have a special value of -1,
which means "ignore axis transformations". Also note that if you add or remove axises, the indexes may change.
You can rotate the series by assigning *both* `AxisIndexX`

to vertical axis and `AxisIndexY`

to the horizontal axis.

#### Linear and logarithmic transformation

Those are simple arithmetic transformations.

#### Auto-scaling transformation

To display several independently scaled series, assign them to two or more axises
and apply `TAutoScaleAxisTransform`

to each axis.
See "axistransf" demo, page "Linear", checkbox "Auto scale".

By using `MinValue`

and `MaxValue`

properties you can control the in graph coordinates
of the auto-scaled series. For example, by setting one transformation to a range from 0 to 1, and another
to a range from 1 to 2, you will confine all the series using the first transformation to the upper half of the chart,
and all the series using the second transformation to the lower half (assuming there are no unassigned series left).

#### User-defined transformation

You can create you own transformation either by inheriting from `TAxisTransform`

,
or, if you prefer "visual" programming, by using `TUserDefinedAxisTransform`

.
In either case there are two basic requirements:

`AxisToGraph`

and`GraphToAxis`

functions should be defined everywhere in data range and inverse of each other (for example, avoid now only dividing, but also multiplying by zero).- functions should be monotonic.

### Extents

## Tools

*TODO*

## Legend

*TODO*

## Marks

*TODO*

## Drawers

*TODO*

*TODO*