convert.threshold.to.er | R Documentation |
These functions can be used to visualise Numbers Needed for Change (or
Numbers Needed to Treat).
erDataSeq
is a helper function to generate an Event Rate Data
Sequence, and it uses convert.threshold.to.er
and
convert.er.to.threshold
to convert thresholds to event rates and vice
versa.
convert.threshold.to.er( threshold, mean, sd, eventIfHigher = TRUE, pdist = stats::pnorm ) convert.er.to.threshold( er, mean, sd, eventIfHigher = TRUE, qdist = stats::qnorm ) erDataSeq( er = NULL, threshold = NULL, mean = NULL, sd = NULL, eventIfHigher = TRUE, pRange = c(1e-06, 0.99999), xStep = 0.01 ) ggNNC( cerDataSeq, d = NULL, eventDesirable = TRUE, r = 1, xlab = "Continuous outcome", plotTitle = c("Numbers Needed for Change = ", ""), theme = ggplot2::theme_bw(), lineSize = 1, cerColor = "#EBF2F8", eerColor = "#172F47", cerLineColor = "#888888", eerLineColor = "#000000", dArrowColor = "#000000", cerAlpha = 0.66, eerAlpha = 0.66, xLim = NULL, xLimAutoDensityTolerance = 0.001, showLegend = TRUE, verticalLineColor = "#172F47", desirableColor = "#00FF00", desirableAlpha = 0.2, undesirableColor = "#FF0000", undesirableAlpha = 0.2, desirableTextColor = "#009900", undesirableTextColor = "#990000", dArrowDistance = 0.04 * max(cerDataSeq$density), dLabelDistance = 0.08 * max(cerDataSeq$density) )
threshold |
If the event rate is not available, a threshold value can
be specified instead, which is then used in conjunction with the mean
( |
mean |
The mean of the control group distribution. |
sd |
The standard deviation (of the control distribution, but assumed to be the same for both distributions). |
eventIfHigher |
Whether scores above or below the threshold are considered 'an event'. |
pdist, qdist |
Distributions to use when converting thresholds to event rates and vice versa; defaults to the normal distribution. |
er |
Event rate to visualise (or convert). |
pRange |
The range of probabilities for which to so the distribution. |
xStep |
Precision of the drawn distribution; higher values mean lower precision/granularity/resolution. |
cerDataSeq |
The |
d |
The value of Cohen's d. |
eventDesirable |
Whether an event is desirable or undesirable. |
r |
The correlation between the determinant and behavior (for mediated NNC's). |
xlab |
The label to display for the X axis. |
plotTitle |
The title of the plot; either one character value, this value if used; if two, they are considered a prefix and suffix to be pre/appended to the NNC value. |
theme |
The theme to use for the plot. |
lineSize |
The thickness of the lines in the plot. |
cerColor |
The color to use for the event rate portion of the control group distribution. |
eerColor |
The color to use for the event rate portion of the experimental group distribution. |
cerLineColor |
The line color to use for the control group distribution. |
eerLineColor |
The line color to use for the experimental group distribution. |
dArrowColor |
The color of the arrow to show the effect size. |
cerAlpha |
The alpha value (transparency) to use for the control group distribution. |
eerAlpha |
The alpha value (transparency) to use for the control group distribution. |
xLim |
This can be used to manually specify the limits for the X axis;
if |
xLimAutoDensityTolerance |
If |
showLegend |
Whether to show the legend (only if showing two distributions). |
verticalLineColor |
The color of the vertical line used to indicate the threshold. |
desirableColor |
The color for the desirable portion of the X axis. |
desirableAlpha |
The alpha for the desirable portion of the X axis. |
undesirableColor |
The color for the undesirable portion of the X axis. |
undesirableAlpha |
The color for the undesirable portion of the X axis. |
desirableTextColor |
The color for the text to indicate the desirable portion of the X axis. |
undesirableTextColor |
The color for the text to indicate the undesirable portion of the X axis. |
dArrowDistance |
The distance of the effect size arrow from the top of the distributions. |
dLabelDistance |
The distance of the effect size label from the top of the distributions. |
These functions are used by nnc()
to show the distributions, and
event rates. They probably won't be used much on their own.
erDataSeq
returns a data sequence; ggNNC
a
ggplot2::ggplot()
.
Gjalt-Jorn Peters & Stefan Gruijters
Maintainer: Gjalt-Jorn Peters gjalt-jorn@userfriendlyscience.com
Gruijters, S. L., & Peters, G. Y. (2019). Gauging the impact of behavior change interventions: A tutorial on the Numbers Needed to Treat. PsyArXiv. doi: 10.31234/osf.io/2bau7
nnc()
### Show distribution for an event rate value of 125 behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125, mean=90, sd=30)); ### If the event occurs under the threshold instead of ### above it behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125, mean=90, sd=30, eventIfHigher = FALSE)); ### ... And for undesirable events (note how ### desirability is an argument for ggNNC, whereas ### whether an event occurs 'above' or 'below' the ### threshold is an argument for erDataSeq): behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125, mean=90, sd=30, eventIfHigher = FALSE), eventDesirable = FALSE); ### Show event rate for both experimental and ### control conditions, and show the numbers ### needed for change behaviorchange::ggNNC(behaviorchange::erDataSeq(threshold=125, mean=90, sd=30), d=.5); ### Illustration of how even with very large effect ### sizes, if the control event rate is very high, ### you'll still need a high number of NNC behaviorchange::ggNNC(behaviorchange::erDataSeq(er=.9), d=1);
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