I'm using Delphi and Fast reports, specifically the TeeChart object inside Fast Reports.
I'm trying to plot a scatter graph (preferably with a line between the points)
Four points of typical X,Y data might look like this
X=10, Y=35
X=15, Y=40
X=23, Y=44
X=27, Y=8
I've set the X axis automatic to false and set a min of 0 and a max of 30.
However, when Teechart plots the points it plots the Y values at the correct height but puts them in X positions 0, 1, 2, 3 instead of 10, 15, 23, 27
This even happens when I hard code the data by setting 'Data Source' to 'Fixed Data' and putting 35;40;44;8 in the Y values box and 10;15;23;27 in the X values box.
How do I set up Teechart to plot the points at the correct X-Y coordinates?
You should use AddXY method, for example:
Series1.AddXY(10, 35);
Series1.AddXY(15, 40);
Series1.AddXY(23, 44);
Series1.AddXY(27, 8);
You should also be able to modify values like this:
Chart1[0].XValues[0]:=10;
Chart1[0].XValues[1]:=15;
Chart1[0].XValues[2]:=23;
Chart1[0].XValues[3]:=27;
Chart1[0].XValues[0]:=35;
Chart1[0].XValues[1]:=40;
Chart1[0].XValues[2]:=44;
Chart1[0].XValues[3]:=8;
That's how it should be done in TeeChart outside of FastReports. If none of those solutions works you might need to contact FastReports technical support.
Related
In Vaadin 14.6.1, I tried to create a Vaadin heatmap foollowing the documentation / example from here.
However, I encountered a few problems/questions, listed in descending order of importance below:
The heatmap supported 30 rows by 30 columns; but when I tried 40 rows by 40 columns, the entire heatmap showed a single color (blue in my case).
Is it possible to manually set the minimum numeric value and maximum numeric value for the color scheme. This way, if I plot my data one day and it has values in the range of 0 to 1, but on another dataset from another day, the numeric values range from between 0 and 0.5, the color scheme range won't automatically change (to being between 0 and 0.5) and confuse the user.
In the documentation, it has the following methods listed, but they do not seem to exist in Vaadin 14.6.1
plotOptions.setBorderColor(SolidColor.WHITE);
plotOptions.setBorderWidth(2);
When I hover over the datapoints, is there a way that the tooltip can only show the numeric value (and not the x, y coordinate or the series name etc.?)
Is there any limit to the number of datapoints? I'm hoping that if #1 above is resolved that I can plot a 100 by 100 (ie 10,000) point heatmap.
If I plot 100by100, there will be many labels on the x and y axis. In my case, the x and y axis are actually numerical, so I did what the documentation suggested and just placed category labels in the xaxis and yaxis spots. However, is there any way to only display every "nth" label, so that the x-axis and y-axis is not so crowded? (This would essentially mimic what Vaadin does for normal line charts' xaxis and yaxis).
I'm not that experienced with Vaadin Chart, but these are the questions that I can comment on:
(1) With 40x40 items you go over the threshold of 1000 in which the Chart switches into "turbo" mode for performance reasons. This seems to not be compatible with the heatmap series. You can disable turbo mode by setting plotOptions.setTurboThreshold(0);
(2) Unfortunately the ColorAxis doesn't support this, it only has an API for min and max color. Definitely a valid use-case though, and it seems to be supported by the Highcharts library that the Vaadin Chart uses under the hood. You should consider opening a feature request for this in the Github repo.
(3) This seems to be a documentation issue. The methods are available in later Vaadin platform versions, but not in 14.6.
(5) In theory not, but in practice there will be a huge performance hit in the browser due to the excessive amount of DOM elements (quick test of 100x100 froze the browser for 10s). I'm afraid the component isn't really made for such extreme use-cases. In this case it might be better to utilize a low-level JS drawing library using the canvas, or draw an image on the server-side and display that in the browser. Maybe you can also consider modifying your use-case so that you only display one slice of your data and allow the user to switch between slices.
I am new to Thingsboard.
Today I created a chart to see temperature from a few sensors.
The problem is, I can see a few vertical marks which are the same:
I.e. two pairs of 28, two pairs of 26, etc.
As to me, it is quite strange… Maybe, it was designed this way, and I simply don’t understand why…
This is caused by rounding: By default, the Y-Axis doesn't show decimal values.
In this example, I have 4 Values: 20.1, 19.7, 20, 20 which are all rounded to 20 in the Y-Axis:
If you change the number of decimals displayed in the settings, it works as expected:
Scenario: I need to draw a plot that has a background image. Based on the information on that image there have to be multiple origins (let's call them 'targets') that can move over time. The movements of these targets will have to be indicated by arrows/vectors where the first vector originates at the location of the target, the second vector originates where the previous vector ended and so on.
The result should look similar to this:
Plot with targets and movement vectors
While trying to implement this, i stumbled upon different questions:
I would use a chart with combined series: a Scatter plot to add the targets at exact x/y locations and a vector plot to insert the vectors. Would this be a correct way?
Since i want to set each vectors starting point to exact x/y coordinates i use rotationOrigin: 'start'. When i now change vectorLength to something other than 20 the vector is still shifted by 10 pixels (http://jsfiddle.net/Chop_Suey/cx35ptrh/) this looks like a bug to me. Can it be fixed or is there a workaround?
When i define a vector it looks like [x, y, length, direction]. But length is a relative unit that is calculated with some magic relative to the longest vector which is 20 (pixels) by default or whatever i set vectorLength to. Thus, the vectors are not connected and the space between them changes depending on plot size axes min/max). I actually want to corellate the length with the plot axis (which might be tricky since the x-axis and y-axis might have different scales). A workaround could be to add a redraw event and recalculate the vectors on every resize and set the vectorLength to the currently longest vector (which again can be calculated to correlate to the axes). This is very cumbersome and i would prefer to be able to set the vectors somehow like [x1, y1, x2, y2] where (x1/y2) denotes the starting- and (x2/y2) the ending-point of the vector. Is this possible somehow? any recommendations?
Since the background image is not just a decoration but relevant for the displayed data to make sense it should change when i zoom in. Is it possible to 'lock' the background image to the original plot min/max so that when i zoom in, the background image is also zoomed (image quality does not matter)?
Combining these two series shoudn't be problematic at all, and that will be the correct way, but it is necessary to change the prototype functions a bit for that the vectors will draw in a different way. Here is the example: https://jsfiddle.net/6vkjspoc/
There is probably the bug in this module and we will report it as new issue as soon as it is possible. However, we made the workaround (or fix) for that and now it's working well, what you can notice in example above.
Vector length is currently calculated using scale, namely - if vectorLength value is equal to 100 (for example), and vector series has two points which looks like that:
{
type: 'vector',
vectorLength: 100,
rotationOrigin: 'start',
data: [
[1, 50000, 1, 120],
[1, 50000, 2, -120]
]
}
Then the highest length of all points is taken and basing on it the scale is calculated for each point, so first one length is equal to 50, because the algorithm is point.length / lengthMax, what you can deduce from the code below:
H.seriesTypes.vector.prototype.arrow = function(point) {
var path,
fraction = point.length / this.lengthMax,
u = fraction * this.options.vectorLength / 20,
o = {
start: 10 * u,
center: 0,
end: -10 * u
}[this.options.rotationOrigin] || 0;
// The stem and the arrow head. Draw the arrow first with rotation 0,
// which is the arrow pointing down (vector from north to south).
path = [
'M', 0, 7 * u + o, // base of arrow
'L', -1.5 * u, 7 * u + o,
0, 10 * u + o,
1.5 * u, 7 * u + o,
0, 7 * u + o,
0, -10 * u + o // top
];
return path;
}
Regarding your question about defining start and end of a vector by two x, y values, you need to refactor entire series code, so that it won't use the vectorLength at all as like as scale, because you will define the points length. I suspect that will be very complex solution, so you can try to do it by yourself, and let me know about the results.
In order to make it works, you need to recalculate and update vectorLength of your vector series inside of chart.events.selection handler. Here is the example: https://jsfiddle.net/nh7b6qx9/
Can I rotate a chart? I need x on vertical axis and y on horizontal axis.
Can I change x value to vertical axis and y value to horizontal axis?
Or can I rotate of the component TChart (xy values stay standard and I flip component 90)?
Thank you.
The easiest solution would probably be to use swap your values or add your X values as YValues and add your y values as XValues.
Ie, let's say you have your X values in an array called Xdata and your Y values in an array called Ydata. You could add your values with this:
Series1->AddXY(Ydata, Xdata);
Maybe I can write - i used a line(fast line) chart.
There
[IMG]http://i68.tinypic.com/29atrw5.png[/IMG]
is Classical graph and image if I rotate it. If I change x-y values as You wrote I get wrong image.
y = f(x) so it paint for x=1, x=2, ... but i need paint x = f(y) for y=1, y=2, y=3
I need something as is point chart - connect handly in paint
I'm not sure if it is possible change axis or rotate component teeChart.
I probably use TImage and will paint it into image.
today i find that teechart have a series "horiz line" (https://www.steema.com/files/public/teechart/java/v1/docs/Tutorials/tutorial1.htm).
But licence is expensive for our company (https://www.steema.com/buy). We need only one chart with this axes.
Do you know if can I install only some update into BCB 6?
Introduction
I am using the TChart component and am finding the options rather confusing and hard to find what I need.
The Left Axis of the chart has a minimum of 0 and a maximum of 5000, the Bottom Axis has a minimum of 0 and a maximum of 52 (weeks in a year).
In my chart I have 2 series that are populated based on values from a record I have created which can be edited at runtime, everything is working good so far.
Problem
Take a look at the below image of part of the chart filled with some random values:
I am not sure if such an option exists or not, but notice from week 4 onwards where no values have been added there is a solid red line.
I don't want the chart to plot values that are less than 0, so in this example from week 4 onwards there should be no more lines (I can confirm that from week 4 onwards I have the values set at -1)
Week 1 to 4 does not show this bottom red line, obviously because the values are greater than 0 and are therefore plotted above the line, but this should make my problem a bit more clearer.
So, how do I prevent the chart from plotting / drawing values that are less than 0, importantly for the Bottom Axis of the chart?
I am sure there must be a simple option somewhere, I just cannot find it if there is one as I am not too familiar with the TChart Component.
You have the possibility when adding values to a series to add them as null.
This will prevent them from showing.
Ken is correct saying that a tricky situation is to handle a single value surrounded by null values.
Picking another series type than FastLine and show dots as well as lines might work better.
For a FastLine series to show gaps, set:
Series1.IgnoreNulls := False;
And to discriminate values below zero:
if (y < 0) then
Series1.AddNullXY(x, y, '')
else
Series1.AddXY(x, y, '');
if y < 0 then
LineSeries1.AddXY(x, y, '', clNone)
else
LineSeries1.AddXY(x, y, '', clRed);