cummin()

cummin(x)

The cummin() function computes the cumulative minimum of a vector, returning a vector of the same length where each element is the minimum of all preceding elements.

Syntax

cummin(x)

Parameters

Parameter	Type	Default	Description
x	numeric	required	A numeric vector

Examples

Basic usage

x <- c(5, 4, 3, 2, 1)

cummin(x)
# [1] 5 4 3 2 1

# With increasing values
y <- c(1, 2, 3, 4, 5)
cummin(y)
# [1] 1 1 1 1 1

# With mixed values
z <- c(3, 1, 4, 1, 5)
cummin(z)
# [1] 3 1 1 1 1

Tracking running minimum

# Stock prices
prices <- c(100, 95, 105, 98, 110, 105, 115)

# Running minimum (lowest so far)
cummin(prices)
# [1] 100  95  95  95  95  95  95

Common Patterns

Drawdown tracking

# Portfolio values
portfolio <- c(10000, 9800, 10500, 9700, 10100, 9500, 10200)

# Maximum peak-to-trough decline
peak <- cummax(portfolio)
drawdown <- (portfolio - cummin(portfolio)) / peak
min(drawdown)
# [1] -0.1020408  # about 10% drawdown

Lowest temperature tracking

# Daily temperatures
temps <- c(72, 68, 75, 65, 70, 62, 71)

# Coldest day so far
cummin(temps)
# [1] 72 68 68 65 65 62 62

See Also

• base::cumsum
• base::cumprod
• base::cummax
• base::min