Re: [opendx-users] simple plotting

[Dan Patnaude]

Maybe this is a fundamental misunderstanding of how DX treats things on my part.  I've updated the data so that I now have four columns: x,y,z,radial velocity The x, y,  and z positions describe a position in space, and the data at that position is the radial velocity. If I assume an age and distance to the remnant, I can decompose the radial velocity into components vx, vy, and vz, but I am still at a loss. When I read in the spreadsheet, how do I tell DX to associate v_radial (or vx,vy,vz) with the position (x,y,z)?  I don't understand how to tell DX that the 1st three columns denote positions, but the 4th column (or 4th, 5th and 6th columns) are data associated with those positions; i.e. column 4 is the x component of the velocity at the position (x,y,z).  Moreover, if I do create a three vector for the velocity components, I can't seem to pass it to the 4th tab in Construct. It returns the following error: ERROR: Construct: Invalid data: origin must be a vector or vector list Here is the layout: ImportSpreadSheet=>Mark(x),Mark(y),Mark(z),Mark(vx),Mark(vy),Mark(vz) Mark(x,y,z)->Compute([x,y,z]) Mark(vx,vy,vz)->Compute([vx,vy,vz]) [x,y,z]->Construct.origin [vx,vy,vz]->Construct.data A little more insight would be helpful. I can't imagine that this is as much of a hassle as it seems to be. I've attached the network and data in case anyone would be kind enough to play around with it.

ejecta.cfg
Description: Binary data

ejecta.dat
Description: Binary data

ejecta.net
Description: Binary data

On May 20, 2005, at 5:29 PM, Chris Pelkie wrote: I'm not sure if you mean you want all the arrows to originate at 0,0,0, as if you snapshot the 'explosion', or if you want each arrow to originate at its x,y,z position, but be directed radially away from 0,0,0. In either case, the solution is the same, but the 'positions' are different. To draw 3-d arrow glyphs in space, you need to have 3-d positions and 3-d data (dep on those positions). You didn't specify what you Mark'ed (I assume column0, column1, column2), so after creating the 3-vector and (unnecessarily Unmark'ing) you have 3-d data on the 1-d positions (a line) autocreated by ImportSpreadsheet (and usually, but not always, worthless). So to emanate all from the origin, compute the 3-vectors as you have already, then feed this array to the 4th input of a Construct. Set origin to 0,0,0. This creates a field with as many 0,0,0 positions as there are data items in the input array. Autoglyph. Color with Autocolor or Color/Colormap. Image. done. To do the second layout, separately Compute the array of 3-d positions and feed it to Construct(origin) and the data array to the same Construct's 4th input (which I can't think of the formal name of off the top of my head, either data or input). Same net as above. Use Print("rd") to watch how each operation changes the data field at the output of each module. ____________________________ Chris Pelkie Vice President      (607) 257-8335 Conceptual Reality Presentations, Inc. 30 West Meadow Drive Ithaca, NY 14850 On May 19, 2005, at 19:41, Daniel Patnaude wrote: Hi- I'm trying to do something which intuitively ought to be quite simple: I have a data file which looks like: x_pos,y_pos,v_radial The data is of ~ 450 ejecta knots in a supernova remnant (3c58 for the curious).  I basically want to make a 'kaboom' type 3-d distribution with the coords x,y,v_rad, since v_rad is effectively a measure of the z displacement from the center. The positions should be marked by an arrow which points radially away from (0,0,0), has a length proportional to the data, and optionally a color based on the value (bluer for positive, redder for negative values). Is this an easy thing to do? So far, all I've been able to do is: ImportSpreadSheet->(Mark x 3, for each value)->Compute (to make a vector)->Unmark->Autoglyph->Image but this only makes a distribution of circles, which looks nice, but isn't quite what I have in mind. Any suggestions? Thanks, Dan ---------------------------------------------------- Daniel Patnaude Smithsonian Astrophysical Observatory 60 Garden St MS-02 Cambridge, MA 02138 [EMAIL PROTECTED] (617) 496-2087