Re: List element extraction
- To: mathgroup at smc.vnet.net
- Subject: [mg53497] Re: List element extraction
- From: bghiggins at ucdavis.edu
- Date: Fri, 14 Jan 2005 08:54:54 -0500 (EST)
- References: <cs5b2r$3rv$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Suppose your list is called 'alist', then the following will do the
task:
Cases[alist, Rule[x_,y_]->y/2,8]
{-2.32422, -2.2271, -2.12914, -2.03027, -1.9303, -1.82906, -1.72629, \
-1.62162, -1.51458, -1.40451, -1.29053, -1.17153, -1.04626, -0.91365, \
-0.773295, -0.626175, -0.476266, -0.33392, -0.217138, -0.135373,
-0.076033}
Cheers,
Brian
Trinanjan Datta wrote:
> How do I extract the x values from the following list and divide them
> by 2:
>
> {{120.664, {x -> -4.64844}}, {
> 118.131, {x -> -4.4542}}, {115.479, {x -> -4.25828}}, {
> 112.697, {x -> -4.06053}}, {109.766, {x -> -3.8606}}, {
> 106.666, {x -> -3.65812}}, {
> 103.372, {x -> -3.45257}}, {99.8501, {x -> -3.24323}}, {
> 96.0571, {x -> -3.02915}}, {
> 91.9343, {x -> -2.80902}}, {87.3996, {x -> -2.58106}}, {
> 82.3355, {x -> -2.34305}}, {76.5712, {x -> -2.09251}}, {
> 69.8594, {x -> -1.8273}}, {61.8567, {x -> -1.54659}}, {
> 52.1348, {x -> -1.25235}}, {40.3287, {x -> -0.952531}}, {
> 26.7404, {x -> -0.66784}}, {13.703, {x -> -0.434276}}, {
> 5.08285, {x -> -0.270745}}, {1.45243, {x -> -0.152066}}}