Convert Time \(t\) into Variable Linearly Depending on \(t\).
Source:R/convert_time2var.R
convert_time2var.Rd
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
orh
. 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') ofvar
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).
See also
Other Conversions and Corrections:
convert_A_MHz_2a()
,
convert_B()
,
convert_a_mT_2A()
,
correct_time_Exp_Specs()
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