# CO2

## Boxplot

Submitted by pmagunia on April 22, 2018 - 3:07 PM

Select any column or the entire dataset option for its boxplot.

## Correlation Coefficient

Submitted by pmagunia on April 22, 2018 - 3:08 PM

Select any two columns or the entire dataset option to compute the correlation coefficient matrix.

## Cumulative Frequency Histogram

Submitted by pmagunia on April 22, 2018 - 3:09 PM

Select any column to plot its cumulative frequency histogram.

## Dotplot

Submitted by pmagunia on April 22, 2018 - 3:10 PM

Select any column for its dotplot.

## Hollow Histogram

Submitted by pmagunia on April 22, 2018 - 3:10 PM

Select any two columns to plot them simultaneously using a histogram.

## Mean

Submitted by pmagunia on April 22, 2018 - 3:11 PM

Select any column to compute the arithmetic mean.

## Pie Chart

Submitted by pmagunia on April 22, 2018 - 3:11 PM

Select any column to create its pie chart.

## Plot

Submitted by pmagunia on April 22, 2018 - 3:07 PM

Select any two columns to plot.

## Regression

Submitted by pmagunia on April 22, 2018 - 3:12 PM

Select any two columns for a simple regression analysis. The first column selected will be the independent variable.

## Stem and Leaf Plots

Submitted by pmagunia on April 22, 2018 - 3:12 PM

Select any column for its stem and leaf plot.

## Summary

Submitted by pmagunia on April 22, 2018 - 2:51 PM

Select any column to compute its mean, variance, and also other summary statistics.

## Visual Summaries

Submitted by pmagunia on April 22, 2018 - 3:13 PM

Select any column for various visual summaries.

Submitted by pmagunia on February 26, 2017 - 11:28 AM
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Documentation

## Carbon Dioxide Uptake in Grass Plants

The CO2 data frame has 84 rows and 5 columns of data from an experiment on the cold tolerance of the grass species Echinochloa crus-galli.

### Usage

CO2

### Format

An object of class c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame") containing the following columns:

Plant

an ordered factor with levels Qn1 < Qn2 < Qn3 < ... < Mc1 giving a unique identifier for each plant.

Type

a factor with levels Quebec Mississippi giving the origin of the plant

Treatment

a factor with levels nonchilled chilled

conc

a numeric vector of ambient carbon dioxide concentrations (mL/L).

uptake

a numeric vector of carbon dioxide uptake rates (umol/m^2 sec).

### Details

The CO2 uptake of six plants from Quebec and six plants from Mississippi was measured at several levels of ambient CO2 concentration. Half the plants of each type were chilled overnight before the experiment was conducted.

This dataset was originally part of package nlme, and that has methods (including for [, as.data.frame, plot and print) for its grouped-data classes.

### Source

Potvin, C., Lechowicz, M. J. and Tardif, S. (1990) “The statistical analysis of ecophysiological response curves obtained from experiments involving repeated measures”, Ecology, 71, 1389–1400.

Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.

### Examples

require(stats); require(graphics)

coplot(uptake ~ conc | Plant, data = CO2, show.given = FALSE, type = "b")
## fit the data for the first plant
fm1 <- nls(uptake ~ SSasymp(conc, Asym, lrc, c0),
data = CO2, subset = Plant == "Qn1")
summary(fm1)
## fit each plant separately
fmlist <- list()
for (pp in levels(CO2\$Plant)) {
fmlist[[pp]] <- nls(uptake ~ SSasymp(conc, Asym, lrc, c0),
data = CO2, subset = Plant == pp)
}
## check the coefficients by plant
print(sapply(fmlist, coef), digits = 3)