Develop Reference

MPAndroidChart set current visible X axis

Using MPAndroidChart, I'm struggling to figure out how to set the current visible x axis values. The use case is simple and I would have thought very common, so I'm sure I must be missing some function which can do this:
Say you have a chart with x axis values 1-100
A user zooms and pans a chart so that the range 60-80 is visible. I want to store these values, so that tomorrow when the user re-launches the app, I can restore the exact viewing state (60-80)
Storing the values is really easy - you can simply call chart.lowestVisibleX and chart.highestVisibleX to get the x axis values. But how do I set them on a new instance of the chart? Unfortunately there doesn't seem to be a chart.setHighestVisibleX or chart.setLowestVisibleX.
This previous question / answer is nearly, but not quite, what I need. The suggestion is to use a combination of chart.moveViewToX(60) and chart.setVisibleXRangeMaximum(20). However as the docs for setVisibleXRangeMaximum state:
Sets the size of the area (range on the x-axis) that should be maximum
visible at once (no further zooming out allowed)
I don't want to prevent further zooming, which is what this does. There must be a way to set the zoom level without actually restricting further zooming - but I can't figure it out. Any suggestions?
Thanks

Just to answer my own question, I decided to workaround this issue by resetting the X range maximum after calling moveViewToX. This appears to work. So the solution would be:
chart.setVisibleXRangeMaximum(20)
chart.moveViewToX(60)
chart.setVisibleXRangeMaximum(100)

How to implement multiple highlight line sliders in line chart

I want to implement single and multiple highlight line sliders in line chart. I am able to get only single highlight line slider with MPAndroidChart (https://github.com/PhilJay/MPAndroidChart) library. But I also need two highlight line sliders to allow the user to select range of values(min and max values) on the chart. Please refer the below image for more information:
Can we achieve the above requirement with any library or we need to draw a custom view?
Any help or guidance will be well appreciated.

In terms of shinobicharts, while the Crosshair could be easily customised to act like one of sliders, in order to have the two sliders you'd probably want to make use of the Annotations feature.
You can create Annotations with custom Views and add them at any X, Y point (in data terms). You can also convert between data values and pixel values via the Axes. It is therefore possible to make the Annotation follow the user's finger as they drag across the screen.
The trickiest part would be placing the circle on the LineSeries at the right Y-value. As I mentioned above you can convert pixel values (e.g. from a user gesture) to data values so you could easily get the X value but the API would leave quite a bit of work up to you in order to get the correct Y value.
This kind of feature is something that is requested quite often and is certainly something we are looking at providing in the future but for now, while possible, it isn't available out-of-the-box.
Disclaimer: I work for shinobicontrols

achartengine time chart set initial range

SOLUTION
Instead of using setInitialRange() I had to set the initial x-values using setXAxisMin() as well as setXAxisMax(). A little bit confusing, I think.
ORIGINAL QUESTION
I'm currently working on a project involving the acharteninge library for drawing time diagrams which works excellent so far. The user is capable of switching between various graphs (one XYMultipleSeriesDataset plus one TimeSeries per graph) via separate buttons. So far, achartengine displays all x values when the graph is shown.
However, I was asked to display only the data captured in the first three hours when the graph is shown, as this information is most relevant. Nevertheless, the user should still be able to scroll to data captured after the first three hours meaning that limiting the x-axis maximum value is not an option.
For example: There are two curves. The first curve is drawn using data captured over a period of 4 hours, while the second curve is created out of data captured over 18 hours.
In the current version my programme initially displays all data of the graph which gets displayed meaning the first curve shows three hours of very relevant data while 1 hour of not so important information is shown too. The "ratio" of the second curve is 3 to 15 (highly significant data vs regular data). As a result, a different amount of high important information is shown when the user compares the two curves making it harder for the user to compare this data, as he has to adjust the zoom manually.
EDIT 01.04.2015 15:46
For setting the initial range I use the XYMultipleSeriesRenderer instance's method setInitialRange(double[] initialRange); which does not affect the graph at all. Below you can see my statement (currentlyProcessedCurve.getRecordStart() is an instance of Joda's DateTime and furhtermore it's the x value of the first displayed point):
public static final int CHART_X_AXIS_INITIAL_MAX = 3;
public static final int CHART_MARGIN_PAN = 45;
...
double[] initialRange = { currentlyProcessedCurve.getRecordStart().minusMinutes(ApplicationSettings.CHART_MARGIN_PAN).toDate().getTime(), currentlyProcessedCurve.getRecordStart().plusHours(ApplicationSettings.CHART_X_AXIS_INITIAL_MAX).toDate().getTime(), 0, 600 };
currentDatasetRenderer.setInitialRange(initialRange);
TIDE (Edit end)
The screenshot below approximately shows how the curve should look initially (Just for making it clear: Please only consider the graphs' shapes, as they should look equal --> What I'm trying to say: I know that the x-axis and the y-axis label of the two screenshots different, but I don't have better pictures yet):
desired initial range
Finally, the following screenshot shows how the curve looks when displayed:
For enabling the user to compare the curves I have locked the y-axis zoom.
Any help is highly appreciated. Thanks in advance!

Have you consider pan option?
With this option you can limit axis maximum, and your chart will show the important data on start, while user can scroll left or right (wherever you have less important data points).
All you need to do is:
set pan enabled for axis you need
set pan limits (so user can't scroll past the last data point)
Hope this helps,
Cheers.

Instead of using XYMultipleSeriesRendererInstance.setInitialRange() I had to set the initial x-values using XYMultipleSeriesRendererInstance.setXAxisMin() as well as XYMultipleSeriesRendererInstance.setXAxisMax().
double xMinValue = ...;
double xMaxValue = ...;
currentDatasetRenderer.setXAxisMin(xMinValue);
currentDatasetRenderer.setXAxisMax(xMaxValue);

does charts (achartengine ) carry dynamically changing capability

Does charts (AChartEngine) have these capability
1.Ability to add or remove legend
Ability to adjust the axis - both x and y (min and max) - ideally by using a finger pinch.
Ability to show a value if you hover over the point
Ability to show, hide a curve on demand

1.Ability to add or remove legend
Yes. Use the setShowLegend() method on the renderer.
Ability to adjust the axis - both x and y (min and max) - ideally by
using a finger pinch.
For interactivity, you should move to the new Codename One charts package (which is based on the aChartEngine library). It provides more features in this area. You can enable pinch zoom and panning by specifying a flag. Pinch zoom currently just works by zooming in (like on a photograph), so it doesn't necessarily adjust the axis. If you can point me to an example of a chart that provides the type of behaviour you're looking for, I can take a look and recommend how it can be achieved.
Ability to show a value if you hover over the point
The ChartComponent (in the new charts package) allows you to override the seriesPressed() and seriesReleased() methods to respond to clicks on points in the chart. You can then display whatever you want in response. These methods are passed events telling you which series (and data point) was pressed.
Ability to show, hide a curve on demand
You can just modify the chart model (e.g. to remove/add a series), then repaint the ChartComponent.

Issues faced while drawing dynamic line graph using AChartEngine in Android

How to stop scrolling of AChartEngine dynamic line graph along the y-axis?
When I dynamically plot values I wish to display the recent plotted value. How to do that?
I wish to plot y- axis values in range 20 to 200 and want to display only 5 values so I have used mRenderer.setYLabels(5); But, when I do so grid lines are displayed for only those values. And user will not be able to know the exact y axis co-ordinate. How to show grid lines for each value and show labels for only some values?
If I manually scroll graph horizontally towards right or left, x-axis labels change. I set range as 0-10 with setXLables(2); but it changes to 0,5,10… How to control this behavior?

These should be 4 separate questions, not numbered ones. So, I will only answer the first one of them:
You can set the min and max displayed values:
renderer.setXAxisMin(minValue);
renderer.setXAxisMax(maxValue);
If by scrolling you mean panning, then this is the way to do:
renderer.setPanEnabled(false, false);
renderer.setZoomEnabled(false, false);