Convert Time $t$ into Variable Linearly Depending on $t$.

Conversion of time ($t$) into variable ($var$), linearly changing in time.

Usage

convert_time2var(
  time.vals,
  time.unit = "s",
  var0,
  var.switch = NULL,
  var.rate,
  var.rate.unit = "s^{-1}"
)

Arguments

time.vals: Numeric value or vector, corresponding to time (points) where the variable var is changed.
time.unit: Character string, time unit defined by s,min or h. Default: time.unit = "s".
var0: Numeric, the initial value (ALSO WITH NEGATIVE SIGN, if required, e.g. negative electrochemical potential).
var.switch: Numeric, the switching point var value, in case when a linear CYCLIC CHANGE (or 'triangular ramp') of var on time is applied (e.g. in cyclic voltammetry). Default: var.switch = NULL (in case there is no such cyclic change).
var.rate: Numeric, corresponding to rate of linear var change (INCLUDING ALSO NEGATIVE SIGN, if required, e.g. in the case of electrochemical reduction or sample cooling).
var.rate.unit: Character string, corresponding to var.rate unit defined by following strings "s^{-1}" $\equiv \text{s}^{-1}$, "min^{-1}" $\equiv \text{min}^{-1}$ or "h^{-1}" $\equiv \text{h}^{-1}$. Default: var.rate.unit = "s^{-1}".

Value

Numeric value or vector of the variable such as electrochemical potential or temperature, linearly changing in time.

Details

The linear relationship between $var$ and time ($t$) can be expressed like $$var = var0 + rate~ t$$ This is especially suitable for time conversion of EPR time series experiments (see e.g. readEPR_Exp_Specs_kin) simultaneously performed either during electrochemical/voltammetric or variable temperature experiment. When cyclic series experiment is performed (e.g. cyclic voltammetry), that $var$ value depends on the switching one, like => $$var = var0 + rate~ t ~~ \text{for} ~~ t \leq t_{\text{switch}}$$ $$var = var_{\text{switch}} - rate\, (t - t_{\text{switch}}) ~~ \text{for} ~~ t \geq t_{\text{switch}}$$ where the $t_{\text{switch}}$, corresponding to $var_{\text{switch}}$, are the quantities at the turning point( see also the var.switch argument).

Examples

## calculate potential after 30 s, starting from 200 mV
## into cathodic direction (reduction) by 5 mV s^{-1}
convert_time2var(30,var0 = 0.2,var.rate = - 0.005)
#> [1] 0.05
#
## heating sample after 5 min starting from 293 K
## by the temperature rate of 4 K min^{-1}
convert_time2var(5,
                 time.unit = "min",
                 var0 = 293,
                 var.rate = 4,
                 var.rate.unit = "min^{-1}")
#> [1] 313
#
## create/evaluate vector containing the applied
## cell potential (in V) from the simultaneously
## performed electrochemical oxidation experiment
## (e.g. cyclic voltammetry from -0.1V to 0.45V and back
## to -0.1V). Time series vector is labeled as "time_s".
time_s <- seq(0,360,by = 18)
E_V <- convert_time2var(time.vals = time_s,
                        var0 = -0.1,
                        var.switch = 0.45,
                        var.rate = 0.003)
## preview
as.matrix(E_V)
#>         [,1]
#>  [1,] -0.100
#>  [2,] -0.046
#>  [3,]  0.008
#>  [4,]  0.062
#>  [5,]  0.116
#>  [6,]  0.170
#>  [7,]  0.224
#>  [8,]  0.278
#>  [9,]  0.332
#> [10,]  0.386
#> [11,]  0.440
#> [12,]  0.406
#> [13,]  0.352
#> [14,]  0.298
#> [15,]  0.244
#> [16,]  0.190
#> [17,]  0.136
#> [18,]  0.082
#> [19,]  0.028
#> [20,] -0.026
#> [21,] -0.080

Convert Time \(t\) into Variable Linearly Depending on \(t\).

Usage

Arguments

Value

Details

See also

Examples