[R] vlookup in R?

[Joshua Wiley]

Does this do what you are looking for?

###########################
#Create data based off what you provided

datasamp <- structure(list(cdf = c(0, 0.00156, 0.0155, 0.053, 0.116, 0.197,
0.288, 0.38, 0.468, 0.548, 0.618, 0.679, 0.732, 0.776, 0.813,
0.844, 0.87, 0.892, 0.91, 0.926, 0.938, 0.949, 0.957, 0.965,
0.971, 0.976, 0.98, 0.983, 0.986, 0.988, 0.99), seq = c(0L, 20L,
40L, 60L, 80L, 100L, 120L, 140L, 160L, 180L, 200L, 220L, 240L,
260L, 280L, 300L, 320L, 340L, 360L, 380L, 400L, 420L, 440L, 460L,
480L, 500L, 520L, 540L, 560L, 580L, 600L), rand = c(0.262123478,
0.964293344, 0.494827113, 0.733726005, 0.800408948, 0.925748466,
0.047578356, 0.266060366, 0.125522629, 0.701193274, 0.915799432,
0.735984375, 0.517838069, 0.042085025, 0.568346202, 0.067140721,
0.71437727, 0.712210456, 0.288460952, 0.185857723, 0.108859523,
0.513351848, 0.22214423, 0.500350963, 0.437818537, 0.851771599,
0.803521836, 0.249824519, 0.859248634, 0.126926481, 0.713431196
)), .Names = c("cdf", "seq", "rand"), class = "data.frame", row.names = c(NA,
-31L))

#use findInterval() to find the row numbers and then return those rows
from the dataframe for the seq column
datasamp[findInterval(x=datasamp$rand, vec=datasamp$cdf),"seq"]

Josh


On Thu, May 27, 2010 at 6:20 PM, Roslina Zakaria <zroslina at yahoo.com> wrote:
> Hi R-users,
>
> I would like to search for the values of seq that match my rand values.  In excel I will use =VLOOKUP(G2,$E$2:$F$32,2).  For example, for rand=.262 it will give me approximately seq=120 and rand=0.964293344, seq=460 and etc.
>
> E           F     G
> cdf         seq   rand
> 0.00E+00    0     0.262123478
> 1.56E-03    20    0.964293344
> 1.55E-02    40    0.494827113
> 5.30E-02    60    0.733726005
> 1.16E-01    80    0.800408948
> 1.97E-01    100   0.925748466
> 2.88E-01    120   0.047578356
> 3.80E-01    140   0.266060366
> 4.68E-01    160   0.125522629
> 5.48E-01    180   0.701193274
> 6.18E-01    200   0.915799432
> 6.79E-01    220   0.735984375
> 7.32E-01    240   0.517838069
> 7.76E-01    260   0.042085025
> 8.13E-01    280   0.568346202
> 8.44E-01    300   0.067140721
> 8.70E-01    320   0.71437727
> 8.92E-01    340   0.712210456
> 9.10E-01    360   0.288460952
> 9.26E-01    380   0.185857723
> 9.38E-01    400   0.108859523
> 9.49E-01    420   0.513351848
> 9.57E-01    440   0.22214423
> 9.65E-01    460   0.500350963
> 9.71E-01    480   0.437818537
> 9.76E-01    500   0.851771599
> 9.80E-01    520   0.803521836
> 9.83E-01    540   0.249824519
> 9.86E-01    560   0.859248634
> 9.88E-01    580   0.126926481
> 9.90E-01    600   0.713431196
>                   0.253425703
>                   0.830195013
>                   0.723929563
>                   0.027588733
>                   0.091067232
>                   0.689504685
>                   0.890469069
>                   0.710440382
> Thank you so much for your help.
>
>
>
>
>        [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>



-- 
Joshua Wiley
Senior in Psychology
University of California, Riverside
http://www.joshuawiley.com/