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[74rk]

I have the following situation: I want to display and calculate the deceleration (speed as a function of the position) of multiple train types where for each train type there are different brake force settings:

Type A, setting 1: -0.2m/s^2
Type A, setting 2: -0.3m/s^2
Type A, setting 3: -0.45m/s^2
Type B, setting 1: -0.15m/s^2
Type B, setting 2: -0.35m/s^2
Type B, setting 3: -0.5m/s^2

In reality I have 8 settings per type and 5 types.

The formula for each x-value is vinit*(#-1)+(0.5*a*(#-1)^2)
The formula for each y-value is vinit+a*(#-1)

note that vinit is initial speed in m/s and a is the value corresponding to type and setting in the list above

I have no clue how to make a list of (x,y)-pairs for each of the type-setting combinations. I need about 300 rows (= seconds) and I would like to either populate the whole table at once and use the masking options to display a subset, or be able to dynamically select a type and setting and plot that. I guess the latter isn't what would normally be done in DataGraph.

Note that I am a newbie.
_________________
René Knuvers
Sr. Engineer - LUCROS Railway Engineering

[Pamela]

The short answer is that you could approach the problem in either way in DG.

First, to make a list of x-y pairs that you would mask, you need to have the numbers 1 to 300 (or how ever many rows you want) repeated for each of your scenarios (6).

Set up a group with you six options and add a column with an ID from 1 to 6 (e.g., Scenario)

Set up two global variables n=6, and rows=300.

Add Two functions:
Scenario = ceil(#/rows)
row# = #-(ceil(#/row)-1)*row
where the number of rows is "row*n"

You can use the Scenario to map to the variable "a" from your list of scenrios.
The row number is then used in place of # in your equation to calculate a list of your x,y pairs.

You can also use global variables, to dynamically calculate the values. Really you could do this a few differnt ways. The DG beta also has a clickable graphs so you could have a bar graph with your options and click on a "bar" to have your line graph update with that option.