I am attempting to retrieve data from a table and convert them to double values in order to graph them. column 0 is filled with time values in the format of "00:00" and column 1 is filled with decimal values.
With this code I seem to have properly retrieved the data and converted the contents on column 1 to double value, but do not know how to convert a String with time values into double values in order to represent number of hours:
int row = tableRadio.getRowCount();
for (int r = 0; r < row; r++) {
double r2 = Double.parseDouble( tableModel.getValueAt(r, 0).toString() );
double r3 = Double.parseDouble( tableModel.getValueAt(r, 1).toString() );
series.add(r2, r3);
}
I keep getting java.lang.NumberFormatException: For input string: "0:00" when attempting to graph this data, which from what I understand is because a colon can not be equated with a number value. But how can I get say, "00:21" to instead show up as "0.21" or something that I can use to graph my data? Any suggestions and examples are welcome.
Use SimpleDateFormat to parse() the time column and create a time series chart, as shown here. Use setDateFormatOverride() on the resulting DateAxis to format the time, as shown here. If necessary, you can change the DateFormatSymbols, as shown here.
So I got it working using @Dawood ibn Kareem's method. Here's the final code that worked for me:
//get number of rows
int row = tableRadio.getRowCount();
for (int r = 0; r < row; r++) {
//get column0's values and convert to String
String time = ( tableModel.getValueAt(r, 0).toString() );
//split time into two arrays
String[] timeSplit = time.split(":");
//convert arrays to doubles
double hours = Double.parseDouble(timeSplit[0]);
double min = Double.parseDouble(timeSplit[1]);
//represent column0 values by number of hours
double col0 = (min / 60) + hours;
//get column1's values and convert to double
double col1 = Double.parseDouble( tableModel.getValueAt(r, 1).toString() );
//add values to series
series.add(col0, col1);
}//end of for loop`
Now all of the table values are converted to doubles and I have gotten them to graph successfully.