Error in r.squaredGLMM() - r

I am constructing GLMMs (using glmer() of "lme4" R package) and sometimes I get an error when estimating R2 values (using r.squaredGLMM() from "MuMIn" package).
The model I am trying to fit is simmilar to this one:
library(lme4)
lmA <- glmer(x~y+(1|w)+(1|w/k), data = data1, family = binomial(link="logit"))
Then, to estime R2, I use:
library(MuMIn)
r.squaredGLMM(lmA)
And I get this:
The result is correct only if all data used by the model has not changed since model was fitted. Error in .rsqGLMM(fam = family(x),
varFx = var(fxpred), varRe = varRe, : 'names' attribute [2] must be the same length as the vector [0]
Do you have any idea why this error appears? For instance, If I use only a single random factor (in this case, (1|w)) this error does not appear.
Here is my dataset:
data1 <-
structure(list(w = structure(c(2L, 2L, 2L, 2L, 2L, 2L, 1L, 2L,
1L, 2L, 1L), .Label = c("CA", "CB"), class = "factor"), k = structure(c(4L,
4L, 3L, 3L, 3L, 4L, 1L, 3L, 2L, 3L, 2L), .Label = c("CAF01-CAM01",
"CAM01", "CBF01-CBM01", "CBM01"), class = "factor"), x = c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 0L), y = c(-0.034973549,
0.671720643, 4.557044729, 5.347170897, 2.634240583, -0.555740207,
4.118277809, 2.599825716, 0.95853864, 4.327804344, 0.057331718
)), .Names = c("w", "k", "x", "y"), class = "data.frame", row.names = c(NA,
-11L))
Any thoughts?

This was a bug that has been fixed in version >= 1.15.8 (soon on CRAN, currently on R-Forge).

Related

R How to tell a (t-test) function the needed column in an indirect way?

This is the data with the two columns 'weight' and 'group':
genderweight <- structure(list(weight = c(95.0626365041014, 65.9189881179415,
64.1289176345525, 66.1688823533661, 81.6245374434498, 85.1845386418439,
81.0348729928744, 92.161156464954, 86.3842380662202, 64.8582493776221,
62.3256566394621, 85.0980797936812, 80.0399859200671, 83.3698935236987,
62.8710960018134, 77.0097819307823, 62.9067362884316, 62.8505200797307,
62.2199243419118, 86.2430806667288, 83.8522826935738, 59.3086045947413,
82.578094058482, 62.9779809883867), group = structure(c(2L, 1L,
1L, 1L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 2L, 2L, 1L, 2L, 1L, 1L,
1L, 2L, 2L, 1L, 2L, 1L), levels = c("F", "M"), class = "factor")), row.names = c(NA,
-24L), class = c("tbl_df", "tbl", "data.frame"))
Package and library needed:
install.packages("rstatix")
library(rstatix)
I would like to use a placeholder in the following function:
t_test(genderweight, weight ~ group, detailed = TRUE)
My placeholder could be named i, for example, and afterwards I would like to run:
i <- "weight"
t_test(genderweight, i ~ group, detailed = TRUE)
Or alternatively, i could be a number, e.g. i = 1 and then I would like to run:
t_test(genderweight,genderweight[,i] ~ group, detailed = TRUE)
For both ways, I get an error message of the following type:
Error in `vec_as_location2_result()`:
! Can't extract columns that don't exist.
✖ Column `genderweight[, 1]` doesn't exist.
Run `rlang::last_error()` to see where the error occurred.
Is there a way to tell the function in an indirect way which column you want for the t-test?

Conditional updating coordinate column in dataframe

I am attempting to populate two newly empty columns in a data frame with data from other columns in the same data frame in different ways depending on if they are populated.
I am trying to populate the values of HIGH_PRCN_LAT and HIGH_PRCN_LON (previously called F_Lat and F_Lon) which represent the final latitudes and londitudes for those rows this will be based off the values of the other columns in the table.
Case 1: Lat/Lon2 are populated (like in IDs 1 & 2), using the great
circle algorithm a midpoint between them should be calculated and
then placed into F_Lat & F_Lon.
Case 2: Lat/Lon2 are empty, then the values of Lat/Lon1 should be put
into F_Lat and F_Lon (like with IDs 3 & 4).
My code is as follows but doesn't work (see previous versions, removed in an edit).
The preperatory code I am using is as follows:
incidents <- structure(list(id = 1:9, StartDate = structure(c(1L, 3L, 2L,
2L, 2L, 3L, 1L, 3L, 1L), .Label = c("02/02/2000 00:34", "02/09/2000 22:13",
"20/01/2000 14:11"), class = "factor"), EndDate = structure(1:9, .Label = c("02/04/2006 20:46",
"02/04/2006 22:38", "02/04/2006 23:21", "02/04/2006 23:59", "03/04/2006 20:12",
"03/04/2006 23:56", "04/04/2006 00:31", "07/04/2006 06:19", "07/04/2006 07:45"
), class = "factor"), Yr.Period = structure(c(1L, 1L, 2L, 2L,
2L, 3L, 3L, 3L, 3L), .Label = c("2000 / 1", "2000 / 2", "2000 /3"
), class = "factor"), Description = structure(c(1L, 1L, 1L, 1L,
1L, 1L, 1L, 1L, 1L), .Label = "ENGLISH TEXT", class = "factor"),
Location = structure(c(2L, 2L, 1L, 2L, 2L, 2L, 2L, 1L, 1L
), .Label = c("Location 1", "Location 1 : Location 2"), class = "factor"),
Location.1 = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L), .Label = "Location 1", class = "factor"), Postcode.1 = structure(c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "Postcode 1", class = "factor"),
Location.2 = structure(c(2L, 2L, 1L, 2L, 2L, 2L, 2L, 1L,
1L), .Label = c("", "Location 2"), class = "factor"), Postcode.2 = structure(c(2L,
2L, 1L, 2L, 2L, 2L, 2L, 1L, 1L), .Label = c("", "Postcode 2"
), class = "factor"), Section = structure(c(2L, 2L, 3L, 1L,
4L, 4L, 2L, 1L, 4L), .Label = c("East", "North", "South",
"West"), class = "factor"), Weather.Category = structure(c(1L,
2L, 4L, 2L, 2L, 2L, 4L, 1L, 3L), .Label = c("Animals", "Food",
"Humans", "Weather"), class = "factor"), Minutes = c(13L,
55L, 5L, 5L, 5L, 522L, 1L, 11L, 22L), Cost = c(150L, 150L,
150L, 20L, 23L, 32L, 21L, 11L, 23L), Location.1.Lat = c(53.0506727,
53.8721035, 51.0233529, 53.8721035, 53.6988355, 53.4768766,
52.6874562, 51.6638245, 51.4301359), Location.1.Lon = c(-2.9991256,
-2.4004125, -3.0988341, -2.4004125, -1.3031529, -2.2298073,
-1.8023421, -0.3964916, 0.0213837), Location.2.Lat = c(52.7116187,
53.746791, NA, 53.746791, 53.6787167, 53.4527824, 52.5264907,
NA, NA), Location.2.Lon = c(-2.7493169, -2.4777984, NA, -2.4777984,
-1.489026, -2.1247029, -1.4645023, NA, NA)), class = "data.frame", row.names = c(NA, -9L))
#gpsColumns is used as the following line of code is used for several data frames.
gpsColumns <- c("HIGH_PRCN_LAT", "HIGH_PRCN_LON")
incidents [ , gpsColumns] <- NA
#create separate variable(?) containing a list of which rows are complete
ind <- complete.cases(incidents [,17])
#populate rows with a two Lat/Lons with great circle middle of both values
incidents [ind, c("HIGH_PRCN_LON_2","HIGH_PRCN_LAT_2")] <-
with(incidents [ind,,drop=FALSE],
do.call(rbind, geosphere::midPoint(cbind.data.frame(Location.1.Lon, Location.1.Lat), cbind.data.frame(Location.2.Lon, Location.2.Lat))))
#populate rows with one Lat/Lon with those values
incidents[!ind, c("HIGH_PRCN_LAT","HIGH_PRCN_LON")] <- incidents[!ind, c("Location.1.Lat","Location.1.Lon")]
I will use the geosphere::midPoint function based off a recommendation here: http://r.789695.n4.nabble.com/Midpoint-between-coordinates-td2299999.html.
Unfortunately, it doesn't appear that this way of populating the column will work when there are several cases.
The current error that is thrown is:
Error in `$<-.data.frame`(`*tmp*`, F_Lat, value = integer(0)) :
replacement has 0 rows, data has 178012
Edit: also posted to reddit: https://www.reddit.com/r/Rlanguage/comments/bdvavx/conditional_updating_column_in_dataframe/
Edit: Added clarity on the parts of the code I do not understand.
#replaces the F_Lat2/F_Lon2 columns in rows with a both sets of input coordinates
dataframe[ind, c("F_Lat2","F_Lon2")] <-
#I am unclear on what this means, specifically what the "with" function does and what "drop=FALSE" does and also why they were used in this case.
with(dataframe[ind,,drop=FALSE],
#I am unclear on what do.call and rbind are doing here, but the second half (geosphere onwards) is binding the Lats and Lons to make coordinates as inputs for the gcIntermediate function.
do.call(rbind, geosphere::gcIntermediate(cbind.data.frame(Lat1, Lon1),
cbind.data.frame(Lat2, Lon2), n = 1)))
Though your code doesn't work as-written for me, and I cannot calculate the same precise values your expect, I suspect the error your seeing can be fixed with these steps. (Data is down at the bottom here.)
Pre-populate the empty columns.
Pre-calculate the complete.cases step, it'll save time.
Use cbind.data.frame for inside gcIntermediate.
I'm inferring from
gcIntermediate([dataframe...
^
this is an error in R
that you are binding those columns together, so I'll use cbind.data.frame. (Using cbind itself produced some ignorable warnings from geosphere, so you can use it instead and perhaps suppressWarnings, but that function is a little strong in that it'll mask other warnings as well.)
Also, since it appears you want one intermediate value for each pair of coordinates, I added the gcIntermediate(..., n=1) argument.
The use of do.call(rbind, ...) is because gcIntermediate returns a list, so we need to bring them together.
dataframe$F_Lon2 <- dataframe$F_Lat2 <- NA_real_
ind <- complete.cases(dataframe[,4])
dataframe[ind, c("F_Lat2","F_Lon2")] <-
with(dataframe[ind,,drop=FALSE],
do.call(rbind, geosphere::gcIntermediate(cbind.data.frame(Lat1, Lon1),
cbind.data.frame(Lat2, Lon2), n = 1)))
dataframe[!ind, c("F_Lat2","F_Lon2")] <- dataframe[!ind, c("Lat1","Lon1")]
dataframe
# ID Lat1 Lon1 Lat2 Lon2 F_Lat F_Lon F_Lat2 F_Lon2
# 1 1 19.05067 -3.999126 92.71332 -6.759169 55.88200 -5.379147 55.78466 -6.709509
# 2 2 58.87210 -1.400413 54.74679 -4.479840 56.80945 -2.940126 56.81230 -2.942029
# 3 3 33.02335 -5.098834 NA NA 33.02335 -5.098834 33.02335 -5.098834
# 4 4 54.87210 -4.400412 NA NA 54.87210 -4.400412 54.87210 -4.400412
Update, using your new incidents data and switching to geosphere::midPoint.
Try this:
incidents$F_Lon2 <- incidents$F_Lat2 <- NA_real_
ind <- complete.cases(incidents[,4])
incidents[ind, c("F_Lat2","F_Lon2")] <-
with(incidents[ind,,drop=FALSE],
geosphere::midPoint(cbind.data.frame(Location.1.Lat,Location.1.Lon),
cbind.data.frame(Location.2.Lat,Location.2.Lon)))
incidents[!ind, c("F_Lat2","F_Lon2")] <- dataframe[!ind, c("Lat1","Lon1")]
One (big) difference is that geosphere::gcIntermediate(..., n=1) returns a list of results, whereas geosphere::midPoint(...) (no n=) returns just a matrix, so no rbinding required.
Data:
dataframe <- read.table(header=T, stringsAsFactors=F, text="
ID Lat1 Lon1 Lat2 Lon2 F_Lat F_Lon
1 19.0506727 -3.9991256 92.713318 -6.759169 55.88199535 -5.3791473
2 58.8721035 -1.4004125 54.746791 -4.47984 56.80944725 -2.94012625
3 33.0233529 -5.0988341 NA NA 33.0233529 -5.0988341
4 54.8721035 -4.4004125 NA NA 54.8721035 -4.4004125")

Error in terms.formula : '.' in formula and no 'data' argument for linear regression

I was writing a simple code for multiple linear regression in R. The code is as follows.
dataset$State = factor (dataset$State,
levels = c ('New York','California','Florida'),
labels = c ('1','2','3') )
#Splitting the dataset
library(caTools)
set.seed(123)
split = sample.split(dataset$Profit, SplitRatio = 0.8)
training_set = subset(dataset$Profit, split == TRUE)
test_set = subset(dataset$Profit, split == FALSE)
#Fitting Multiple Linear Regression to the Training set
regressor = lm(formula = Profit ~ ., data = training_set)
But i get this error when running.
Error in terms.formula(formula, data = data) : '.' in formula and
no 'data' argument
Why gives such an error?
dataset at https://drive.google.com/drive/folders/1M5HAKs1s2ABYMEzVYMwWUaATlCw2ayZC?usp=sharing
Thanks for making this reproducible
dataset <-
structure(list(R.D.Spend = c(165349.2, 162597.7, 153441.51, 144372.41,
142107.34, 131876.9, 134615.46, 130298.13, 120542.52, 123334.88,
101913.08, 100671.96, 93863.75, 91992.39, 119943.24, 114523.61,
78013.11, 94657.16, 91749.16, 86419.7, 76253.86, 78389.47, 73994.56,
67532.53, 77044.01, 64664.71, 75328.87, 72107.6, 66051.52, 65605.48,
61994.48, 61136.38, 63408.86, 55493.95, 46426.07, 46014.02, 28663.76,
44069.95, 20229.59, 38558.51, 28754.33, 27892.92, 23640.93, 15505.73,
22177.74, 1000.23, 1315.46, 0, 542.05, 0), Administration = c(136897.8,
151377.59, 101145.55, 118671.85, 91391.77, 99814.71, 147198.87,
145530.06, 148718.95, 108679.17, 110594.11, 91790.61, 127320.38,
135495.07, 156547.42, 122616.84, 121597.55, 145077.58, 114175.79,
153514.11, 113867.3, 153773.43, 122782.75, 105751.03, 99281.34,
139553.16, 144135.98, 127864.55, 182645.56, 153032.06, 115641.28,
152701.92, 129219.61, 103057.49, 157693.92, 85047.44, 127056.21,
51283.14, 65947.93, 82982.09, 118546.05, 84710.77, 96189.63,
127382.3, 154806.14, 124153.04, 115816.21, 135426.92, 51743.15,
116983.8), Marketing.Spend = c(471784.1, 443898.53, 407934.54,
383199.62, 366168.42, 362861.36, 127716.82, 323876.68, 311613.29,
304981.62, 229160.95, 249744.55, 249839.44, 252664.93, 256512.92,
261776.23, 264346.06, 282574.31, 294919.57, 0, 298664.47, 299737.29,
303319.26, 304768.73, 140574.81, 137962.62, 134050.07, 353183.81,
118148.2, 107138.38, 91131.24, 88218.23, 46085.25, 214634.81,
210797.67, 205517.64, 201126.82, 197029.42, 185265.1, 174999.3,
172795.67, 164470.71, 148001.11, 35534.17, 28334.72, 1903.93,
297114.46, 0, 0, 45173.06), State = structure(c(1L, 2L, 3L, 1L,
3L, 1L, 2L, 3L, 1L, 2L, 3L, 2L, 3L, 2L, 3L, 1L, 2L, 1L, 3L, 1L,
2L, 1L, 3L, 3L, 1L, 2L, 3L, 1L, 3L, 1L, 3L, 1L, 2L, 3L, 2L, 1L,
3L, 2L, 1L, 2L, 2L, 3L, 2L, 1L, 2L, 1L, 3L, 2L, 1L, 2L), .Label = c("1",
"2", "3"), class = "factor"), Profit = c(192261.83, 191792.06,
191050.39, 182901.99, 166187.94, 156991.12, 156122.51, 155752.6,
152211.77, 149759.96, 146121.95, 144259.4, 141585.52, 134307.35,
132602.65, 129917.04, 126992.93, 125370.37, 124266.9, 122776.86,
118474.03, 111313.02, 110352.25, 108733.99, 108552.04, 107404.34,
105733.54, 105008.31, 103282.38, 101004.64, 99937.59, 97483.56,
97427.84, 96778.92, 96712.8, 96479.51, 90708.19, 89949.14, 81229.06,
81005.76, 78239.91, 77798.83, 71498.49, 69758.98, 65200.33, 64926.08,
49490.75, 42559.73, 35673.41, 14681.4)), .Names = c("R.D.Spend",
"Administration", "Marketing.Spend", "State", "Profit"), row.names = c(NA,
-50L), class = "data.frame")
The issue is with subsetting. Replace
training_set = subset(dataset$Profit, split == TRUE)
test_set = subset(dataset$Profit, split == FALSE)
with
training_set = subset(dataset, subset = split)
test_set = subset(dataset, subset = !split)
lm(formula = Profit ~ ., data = training_set)
#Call:
#lm(formula = Profit ~ ., data = training_set)
#
#Coefficients:
# (Intercept) R.D.Spend Administration Marketing.Spend
# 4.965e+04 7.986e-01 -2.942e-02 3.268e-02
# State2 State3
# 1.213e+02 2.376e+02

Interpretation of error in sem.coef

I am trying to run a sem with a random effect in piecewiseSEM. My model runs with no error, and sem.fit() also runs with no error or warnings. However, when I run sem.coefs() I get the following warning:
1: In if (grepl("cbind", deparse(formula(x)))) all.vars(formula(x))[-c(1:2)] else all.vars(formula(x)) :
the condition has length > 1 and only the first element will be used
Any ideas what this warning is about or what it means? Given it's a warning and not an error, the code still runs and give me estimates, but can I trust the estimates?
Thanks!
EDIT
#code:
library(piecewiseSEM)
library(nlme)
avg.forb<-list( lme(nitrogen_variation~nat+impervious+precip.variation,random=~1|site/species,control = lmeControl(opt = "optim"),forb), lme(po4_variation~nat+impervious+precip.variaton,random=~1|site/species,control = lmeControl(opt = "optim"),forb),
lme(nitrogen~nat +impervious+precip.variation,random=~1|site/species,control = lmeControl(opt = "optim"), forb),
lme(po4 ~nat +impervious+precip.variation,random=~1|site/species,control = lmeControl(opt = "optim"),forb), lme(avg.height~nat+impervious+po4+po4_variation+nitrogen+nitrogen_variation+precip.variation+n_i, random=~1|site/species,control =lmeControl(opt="optim"),forb), lme(avg.culms~nat+impervious+po4+po4_variation+nitrogen+nitrogen_variation+precip.variation+n_i,random=~1|site/species,control = lmeControl(opt = "optim"), forb), lme(avg.chloro~nat+impervious+po4+po4_variation+nitrogen+nitrogen_variation+precip.variation+n_i,random=~1|site/species, control =lmeControl(opt="optim"),forb), lme(avg.sla~nat+impervious+po4+po4_variation+nitrogen+nitrogen_variation+precip.variation+n_i,random=~1|site/species, control = lmeControl(opt = "optim"),forb))
sem.fit(avg.forb, conditional=T, forb) #this code gives the above error message
#data subset:
structure(list(site = structure(c(1L, 1L, 1L, 2L, 2L, 3L), .Label = c("Baker", "Cronkelton", "Delaware"), class = "factor"), species = structure(c(1L, 4L, 6L, 2L, 3L, 5L), .Label = c("apocynum cannabinum", "aster ericoides", "aster lanceolatus var. interior", "cirsium arvense", "impatiens capensis", "typha angustifolia"), class = "factor"), n_i = structure(c(2L,
1L, 1L, 2L, 2L, 2L), .Label = c("i", "n"), class = "factor"),nat=structure(c(1L, 1L, 1L, 1L, 1L, 2L), .Label = c("1", "2"), class = "factor"), impervious = structure(c(2L, 2L, 2L, 1L, 1L, 1L), .Label = c("1", "2"), class = "factor"), precip_variation = c(70.24882178, 70.24882178, 70.24882178, 21.92460821, 21.92460821, 18.90115299), po4 = c(-2.203425667,
-2.204119983, -2.20481541, -1.845271793, -1.844967771, -2.417936637), po4_variation = c(0.8011, 0.801, 0.8009, 0.4839, 0.484, 0.5229), nitrogen = c(0.00627, 0.00626, 0.00625, 0.00432, 0.00433, 0.01018), nitrogen_variation = c(0.7739, 0.7738, 0.7737, 0.5435, 0.5436, -0.1251), avg.height = c(99.1, 113.5559506, 191.4111012, 73.72222025, 35.42222025, 59.52222025), avg.culms = c(0.492915384, 0.78612011, 0.884606749, 0.96483549, 0.819543936, 0.831087338), avg.sla = c(179.3510333, 149.0332471, 68.77888941, 334.2177912, 798.7581389, 443.2005556), avg.chloro = c(0.900670513, 0.790832282, 0.965532685, 0.565585484, 1.106203493, 0.970209082)), .Names = c("site", "species", "n_i", "nat", "impervious", "precip_variation", "po4", "po4_variation", "nitrogen", "nitrogen_variation", "avg.height", "avg.culms", "avg.sla", "avg.chloro"), row.names = c(NA, 6L), class = "data.frame")

How to generate facetted ggplot graph where each facet has ordered data?

I want to sort my factors (Condition, Parameter and SubjectID) by MeanWeight and plot MeanWeight against SubjectID such that when faceted by Condition and Parameter, MeanWeight appears in descending order.
Here is my solution, which isn't giving me what I want:
dataSummary <- structure(list(SubjectID = structure(c(1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L, 4L, 4L, 4L), .Label = c("s001",
"s002", "s003", "s004"), class = "factor"), Condition = structure(c(1L,
1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L), .Label = c("1", "2", "3"), class = "factor"), Parameter = structure(c(1L,
2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L, 2L, 3L, 1L, 2L,
3L), .Label = c("(Intercept)", "PrevCorr1", "PrevFail1"), class = "factor"),
MeanWeight = c(-0.389685536725783, 0.200987679398502, -0.808114314421089,
-0.10196105040707, 0.0274188815763494, 0.359978984195839,
-0.554583879312783, 0.643791202050396, -0.145042221940287,
-0.0144598460145723, -0.225804028997856, -0.928152539784374,
0.134025102103562, -0.267448309989731, -1.19980109795115,
0.0587152632631923, 0.0050656268880826, -0.156537446664213
)), .Names = c("SubjectID", "Condition", "Parameter", "MeanWeight"
), row.names = c(NA, 18L), class = "data.frame")
## Order by three variables
orderWeights <- order(dataSummary$Condition, dataSummary$Parameter, dataSummary$SubjectID, -dataSummary$MeanWeight)
## Set factors to the new order. I expect this to sort for each facet when plotting, but it doesn't seem to work.
conditionOrder <- dataSummary$Condition[orderWeights]
dataSummary$Condition <- factor(dataSummary$Condition, levels=conditionOrder)
paramOrder <- dataSummary$Parameter[orderWeights]
dataSummary$Parameter <- factor(dataSummary$Parameter, levels=paramOrder)
sbjOrder <- dataSummary$SubjectID[orderWeights]
dataSummary$SubjectID <- factor(dataSummary$SubjectID, levels=sbjOrder)
## Plot
ggplot(dataSummary, aes(x=MeanWeight, y=SubjectID)) +
scale_x_continuous(limits=c(-3, 3)) +
geom_vline(yintercept = 0.0, size = 0.1, colour = "#a9a9a9", linetype = "solid") +
geom_segment(aes(yend=SubjectID), xend=0, colour="grey50") +
geom_point(size=2) +
facet_grid(Parameter~Condition, scales="free_y")
I tried a few other approaches, but they didn't work either:
dataSummary <- dataSummary[order(dataSummary$Condition, dataSummary$Parameter, dataSummary$SubjectID, -dataSummary$MeanWeight),]
or this one
dataSummary <- transform(dataSummary, SubjectID=reorder(Condition, Parameter, SubjectID, MeanWeight))
You can order your data and plot it. However, the labels no longer correspond to Subject ID's, but to the reordered subjects. If that is not what you want, you cannot use faceting but have to plot the parts separately and use e.g.grid.arrangeto combind the different plots.
require(plyr)
## Ordered data
datOrder <- ddply(dataSummary, c("Condition", "Parameter"), function(x){
if (nrow(x)<=1) return(x)
x$MeanWeight <- x$MeanWeight[order(x$MeanWeight)]
x
})
## Plot
ggplot(datOrder, aes(x=MeanWeight, y=SubjectID)) +
scale_x_continuous(limits=c(-3, 3)) +
geom_vline(yintercept = 0.0, size = 0.1, colour = "#a9a9a9", linetype = "solid") +
geom_segment(aes(yend=SubjectID), xend=0, colour="grey50") +
geom_point(size=2) +
facet_grid(Parameter~Condition) +
scale_y_discrete(name="Ordered subjects")

Resources