blq_trans function

A transform for ggplot2 with data that may be below the lower limit of quantification

If the lloq is not provided, it will be estimated from the data as the minimum value above zero.

blq_trans(lloq, x, multiplier = 0.5, lloq_text)

blq_log_trans(lloq, x, multiplier = 0.5, base = 10, lloq_text)

Arguments

• lloq: The value of the lower limit of quantification as a numeric scalar

• x: (only used if lloq is missing), the data for lloq

  estimation.

• multiplier: When data are < lloq, they are replaced by lloq*multiplier for display.

• lloq_text: The text to use on the axis to indicate values < lloq. It will be automatically set to paste0("<", lloq) if missing.

• base: The base for the logarithm

Returns

A "trans" object based on the scales package for BLQ data.

Functions

• blq_log_trans(): Log-scale transformation with BLQ

Examples

## Not run:

library(ggplot2)
ggplot(data=data.frame(x=1:10, y=1:10), aes(x=x, y=y)) +
  geom_point()

ggplot(data=data.frame(x=1:10, y=1:10), aes(x=x, y=y)) +
  geom_point() +
  scale_x_continuous(trans=blq_trans(lloq=3))

ggplot(data=data.frame(x=1:10, y=1:10), aes(x=x, y=y)) +
  geom_point() +
  scale_x_continuous(trans=blq_log10_trans(lloq=3))
## End(Not run)

See Also

Other BLQ Transformation: breaks_blq_general(), estimate_lloq(), ftrans_blq_linear(), itrans_blq_linear(), label_blq()