This component has been awarded the "Delphi™ Choice '96" award from The Delphi Information Connection !
The component RChart is an easy to use scientific chart component. It provides the most basic features for displaying charts in an arbitrary coordinate system. You can set up both the dimensions of the chart on the screen and the range of the real-valued data area in the chart. The component automatically creates suitable scales in a 1-2-5 raster (both linear and logarithmic) and provides flicker-free display of animated drawings. In addition, there are built-in routines for zooming and panning the data window.
The unit RCHART is part of the SDL Component Suite. A screen shot of an example program shows how simple it is to create a chart by using the component RChart. More details can be found in the online help pages.
Following is a short list of sample programs showing the functionality of RChart.
More programs can be found here.
| Histograms | 
A simple application to display bargraphs using RCHART. The angle, depth and height of the bars can be changed. |
rch3dbar.zip (303 kB) |
| Process Control |  Shows how to implement a simple running chart for process control. The chart is based on RCHART and displays the last two minutes of data acquired from a virtual process. |
processc.zip
(315 kB) |
| Shared Diagrams | 
This application nicely shows how set up several RCHARTs which share common data. |
rcshared.zip
(295 kB) |
| Running Charts |  RCHART is used to display a "running" chart like in chart recorders. |
rchfifo.zip
(299 kB) |
What's new:
- Release 9.0 [May-28, 2007]
- TSmithChart is a new component derived from RChart. It supports Smith charts which are commonly used in electronics and electrical engineering
- new method SetEqualScales implemented
- new method SetEqualScalesXOnly implemented
- new method SetEqualScalesYOnly implemented
- mouse wheel events are now published
- function FindUsedLayers implemented
- improvement: the background color of dashed lines is now controlled by the property FillColor
- improvement of the methods AutoRange, AutoRangeXOnly, and AutoRangeYOnly
- bug fix: AddTextLabel now works as expected (bug was introduced with release 8.5)
- bug fix: mouse cursor adjusts its image according to MouseAction (bug was introduced with release 8.5)
- bug fix: changing the range of any axis does no longer force several repaints
- bug fix: rectangles and ellipses are now filled with the correct color after switching from transparent to opaque items
- bug fix: maZoomWind now keeps scale ratio of axes if IsoMetric is TRUE
- bug fix: number of grid lines per axis is no longer limited to 50 (new limit is 250)
- Release 8.5 [Feb-18, 2006]
- OnMouseLeave and OnMouseEnter events implemented
- BackGroundImg extended to display colored background area
- MarginTop, MarginLeft, MarginRight, MarginBottom are introduced instead of TRim, LRim, RRim, and BRim
- bug fix: layer number of text label is correctly assigned now
- bug fix: AutoRange, AutoRangeXOnly, and AutoRangeYOnly now work correctly if Layer is set to a zero value
- bug fix: CrossHair.Layer property cannot be set to illegal values anymore
- constant MaxNumLayers moved to SDLBASE and renamed to MAXNUMRCLAYERS
- text labels now support vertical alignment
- bug fix: LoadData (FName, TRUE) now correctly appends data (bug was introduced with release 8.0)
- bug fix: initialisation of scale positions in Light Edition was wrong
- Release 8.2 [Nov-03, 2004]
- new abstract base class TCustomRChart introduced (as an ancestor of TRChart and the future TQuickChart)
- bug fix: number of tickmarks does not jitter when an axis, whose range is a multiple of 2 or 5, is shifted
- Release 8.1 [Aug-29, 2004]
- available for Delphi™ 8 for .NET
- TRChart is now inherited from TCustomControl (instead of TGraphicControl)
- the events OnKeyUp, OnKeyDown, and OnKeyPress are now available
- new property JointLayers allows to couple axes of specific layers
- new array property LayerVisible controls visibility of data belonging to a specfic layer
- new methods AllTextLabelsOff and SetTextLabel implemented
- FindMinMax can now be layer specific
- SetRange and AutoRange may now set the range of all layers at once
- AutoRangeXOnly and AutoRangeYOnly implemented
- bug fix: text alignment of text labels is now independent of alignment changes in any events
- bug fix: AddTextLabel now sets all properties correctly
- bug fix: invalid index into the text label array does no longer generate a general access violation
- bug fix: FillColor is now correctly processed after Text method
- bug fix: OnScaleTickDrawn is now triggered for x-axes, too
- bug fix: grid does not overwrite axes (bug was introduced with Rel. 8.0)
- Release 8.0 [Apr-15, 2004]
- RChart now provides up to 16 independently scaled layers
- improved performance and easier access to the chart elements by replacing the linked list by a dynamic array (DataContainer)
- drawing speed of crosshairs improved significantly
- short tick marks can now be displayed on all types of y axes (not only on log. axes)
- TDrawCan replaced by TrcChartItem
- ItemType renamed to TrcItem
- SaveLinkedList, SaveLinkedListASC, and LoadLinkedList renamed to SaveData, SaveDataASC, and LoadData
- new properties NumItems and AllocSize
- property SuppressPaint implemented
- MouseCursorFixed is now TRUE by default
- ScaleColor renamed to ChartFrameColor
- CopyToOpenPrinter and PrintIt provide now high resolution, CopyToOpenPrinterHiRes and PrinitItHiRes are no longer available
- CopyToWMF has now black and white option
- CopyToClipboardWMF implemented
- TScaleType moved to SDLBase
- TDtLabel moved to SDLBase
- YearLengthType renamed to TYearLength and moved to SDLBase
- DateOrderType renamed to TDateOrder and moved to SDLBase
- DateForTimeType renamed to TDateForTime and moved to SDLBase
- TTxtLblMode moved to unit SDLBASE
- TShadowStyle moved to unit SDLBASE
- type declaration ZoomStateType has been renamed to TZoomState and moved to unit SDLBASE
- TRFrameStyle replaced by TFrameStyle (of unit SDLBase)
- TZoomPanEvent has been moved to SDLBASE
- DrawMarkOnCanvas has been moved to SDLBASE
- TCrossHair is now part of SDLBASE
- type declaration FigType renamed to TFigType and moved to SDLBase
- PDrawCan discarded (no longer needed)
- bug fix: TimeSeparator now works correctly
- bug fix: CopyToWMF now performs correct clipping of chart data
- bug fix: background image editor now works properly
- bug fix: ScaleSelectedItems did not correctly scale elements with more than one reference point (i.e. lines, rectangles, ellipses, etc)
- Release 7.2 [Mar-23, 2003]
- RCHART is now part of ChartPack
- new event OnBeforeRenderData allows to draw on chart canvas beneath the chart data
- bug fix: logarithmic grids are now drawn correctly if GridDx/GridDy is -2 or -3
- bug fix: text labels have been printed with huge fonts
- Release 7.0 [Sep-15, 2002]
- available for Delphi™ 7.0
- the unit is now CLX compatible
- new method Arrow to draw arrows in a chart
- CopyToWMF is now again available
- size of ZoomHistory stack increased to a maximum of 16 entries
- new property ZoomStack: values of ZoomHistory are now directly accessible
- event OnResize published
- bug fix: ClearZoomHistory did not really clear the stack but set only the stack pointer
- bug fix: an excess number of differently colored filled graphics elements do no longer corrupt color palette (resulting in black artefacts when using tkRect, tkRectFrame, tkEllipse, and tk3DBar)
- bug fix: OnScaleTickDrawn now correctly sets the parameter CurrentTickPos
- Release 6.5 [May-28, 2002]
- available for C++Builder™ 6.0
- RChart now supports drag and drop
- additional symbols for method MarkAt
- new method DrawMarkOnCanvas
- type declaration InscriptStr and LabelStr discarded to become compatible with BCB 6
- bug fix: logarithmic axis do no longer cut trailing zeroes in exponents
- bug fix: crosshair is no longer drawn outside of chart window if 3D shadow is enabled
- bug fix: text label border line has now always a width of 1 pixel
- bug fix: CopyToOpenPrinterHires now prints correctly with landscape orientation
- Release 6.0 [Aug-06, 2001]
- available for Delphi™ 6.0
- new properties XAxisPos and YAxisPos implemented
- property ClassicLayout implemented
- MouseBox now works more intuitively (left mouse button has to be kept pressed while drawing the mouse box)
- MouseBoxAbort implemented
- OnDataRendered and OnScalesRendered events implemented
- OnScaleTickDrawn event implemented
- bug fix: TextLabels did not display correctly with solid background color
- bug fix: AddTextLabel now accepts parameters PosX, PosY as floating point values
- bug fix: Y-axis using the ftTime format is drawn correctly for inverted scales (RangeLoY > RangeHiY)
- bug fix: inverted numeric scales now draw the top most scale tick correctly (occurred in rare circumstances)
- bug fix: memory for text labels fonts is now correctly allocated
- bug fix: FindNearestItemScreen does not create "integer overflow" error when zoomed in by a large factor
- bug fix: property editor form for BackgroundImg is now declared in interface section
- bug fix: zoom box now follows the mouse correctly if MouseAction is maZoomWind and Isometric is TRUE
- Release 5.5 [Jun-09, 2000]
- RChart is now available for C++Builder™ 5
- published property Anchors and Contraints
- bug fix: the mouse cursor is reset to its default image when leaving the chart
- ClearZoomHistory implemented
- bug fix: zoom by mouse, SetRange and AutoRange is now handled correctly if property IsoMetric is true
- shadow of text labels implemented (properties TextLabels[].Mode, TextLabels[].ShadowDx, TextLabels[].ShadowDy, and TextLabels[].ColorShadow)
- multiline labels implemented
- MoveToRelPix and DrawToRelPix implemented
- bug fix: properties MousePosX, MousePosY, CrossHair1..4, IdAbscissa, IdOrdinate, MinTickX, MinTickY can now also be read by C++ programs (problem was due to a bug in BCB3, 4 & 5, but not in BCB1)
- Release 5.0 [Sep-25, 1999]
- RChart is no longer available for Delphi™ 2
- RChart is now available for Delphi™ 5
- chart elements are now stored in a doubly linked list
- LoadLinkedList and SaveLinkedList use a new file format
- new property LastItemOfLinkedList
- runtime version does no longer contain property editor
- PenStyle implemented
- MarkAt has now 14 more symbols
- cross hairs are now accessible as properties CrossHair1...CrossHair4
- cross hairs can now be moved interactively by mouse (MouseAction = maDragCrossH)
- DecPlaceX and DecPlaceY extended to a maximum of 12 digits
- RangeLoX, RangeHiX, RangeLoY, and RangeHiY are now of type "extended" for better accuracy when zooming into very small regions
- new properties MinRangeX and MinRangeY
- OnCrossHairMove event implemented
- data sharing between several charts implemented (property UseDataOf)
- user-defined text labels implemented (property TextLabels)
- AddTextLabel implemented
- OnTextLabelMove event implemented
- FtTime displays now down to milliseconds
- RemoveItemByClass implemented
- resolution problems with labeling of axes resolved
- bug fix: MarkAt (items 13, 14, 15) are now correctly filled
- bug fix: ftDateTime can now handle dates before 1900 correctly
- bug fix: zero values of RangeHiX/Y and RangeLoX/Y are now correctly loaded
- bug fix: CrossHairPosY now returns y value correctly
- bug fix: ItemCount is now correct after LoadLinkedList (FName, true)
- bug fix: AutoRange now works correctly for logarithmix scales
- bug fix: background bitmap editor in D4 now works correctly