The below "MWE code 1" works as intended. It interpolates the values the user inputs into the matrix (id = input2) over the slider input periods (id = input1). Additional scenarios are generated with the click of the single action button which triggers a modal (for later purposes). For illustrative purposes, each scenario is linearly adjusted by a random variable.
I'm trying to adapt the above where additional user inputs into the matrix (always in column groupings of 2, for the 2 values to interpolate) are automatically added to the results function and plotted, without clicking the action button.
The below "MWE code 2" is my beginning of this implementation, and I end at my current knowledge. (Note the input matrix which expands in groups of 2 columns, and the elimination of the runif() inflator since presumably each added scenario will be different). How can I modify MWE code 2 to accomplish this? I am stuck.
MWE code 1:
library(shiny)
library(tidyverse)
library(ggplot2)
library(shinyMatrix)
interpol <- function(a,b){ # a = periods, b = matrix inputs
c <- rep(NA,a)
c[1] <- b[1]
c[a] <- b[2]
c <- approx(seq_along(c)[!is.na(c)],c[!is.na(c)],seq_along(c))$y # this interpolates
return(c)}
ui <- fluidPage(
sliderInput('input1','Periods to interpolate (input1):',min=2,max=10,value=10),
matrixInput("input2",
label = "Values to interpolate (input2):",
value = matrix(c(1,5),1,2,dimnames = list(NULL,c("Value 1","Value 2"))),
rows = list(names = FALSE),
class = "numeric"),
actionButton("add", "Add scenario"),
plotOutput("plot")
)
server <- function(input, output, session) {
results <- function(){interpol(req(input$input1),req(input$input2))}
numScenarios <- reactiveValues(numS=1)
observeEvent(input$add, {showModal(modalDialog(footer = modalButton("Close")))
numScenarios$numS <- (numScenarios$numS 1)})
output$plot <- renderPlot({
req(input$input1,input$input2)
v <- lapply(1:numScenarios$numS,
function(i) tibble(Scenario=i,X=1:input$input1,Y=runif(1) results())
) %>% bind_rows()
v %>% ggplot() geom_line(aes(x=X, y=Y, colour=as.factor(Scenario)))
})
}
shinyApp(ui, server)
MWE code 2:
library(shiny)
library(tidyverse)
library(ggplot2)
library(shinyMatrix)
interpol <- function(a,b){ # a = periods, b = matrix inputs
c <- rep(NA,a)
c[1] <- b[1]
c[a] <- b[2]
c <- approx(seq_along(c)[!is.na(c)],c[!is.na(c)],seq_along(c))$y # this interpolates
return(c)}
ui <- fluidPage(
sliderInput('input1','Periods to interpolate (input1):',min=2,max=10,value=10),
matrixInput("input2",
label = "Values to interpolate (input2) where first row lists scenario number:",
value = matrix(c(1,5),1,2,dimnames = list(NULL,c("Value 1","Value 2"))),
cols = list(extend = TRUE, delta = 2, delete = TRUE, names = TRUE,
editableNames = FALSE, multiheader=TRUE),
rows = list(names = FALSE),
class = "numeric"),
actionButton("add", "Add scenario"),
plotOutput("plot")
)
server <- function(input, output, session) {
results <- function(){interpol(req(input$input1),req(input$input2))}
numScenarios <- reactiveValues(numS=1)
observeEvent(input$add, {showModal(modalDialog(footer = modalButton("Close")))
numScenarios$numS <- (numScenarios$numS 1)})
output$plot <- renderPlot({
req(input$input1,input$input2)
v <- lapply(1:numScenarios$numS,
function(i) tibble(Scenario=i,X=1:input$input1,Y=results())
) %>% bind_rows()
v %>% ggplot() geom_line(aes(x=X, y=Y, colour=as.factor(Scenario)))
})
observe({
req(input$input2)
mm <- input$input2
colnames(mm) <- trunc(1:ncol(mm)/2) 1
isolate(updateMatrixInput(session, "input2", mm))
})
}
shinyApp(ui, server)
See explanatory images below:
CodePudding user response：
Edit: I'd suggest using a row-based matrixInput. This makes your life much easier, as you don't have to reshape the matrix before passing it to your custom function etc.
Please check the following:
library(shiny)
library(shinyMatrix)
library(dplyr)
library(ggplot2)
interpol <- function(a, b) {
# a = periods, b = matrix inputs
c <- rep(NA, a)
c[1] <- b[1]
c[a] <- b[2]
c <- approx(seq_along(c)[!is.na(c)], c[!is.na(c)], seq_along(c))$y # this interpolates
return(c)
}
ui <- fluidPage(
titlePanel("myMatrixInput"),
sidebarLayout(
sidebarPanel(
matrixInput(
"myMatrixInput",
label = "Values to interpolate (myMatrixInput) where first row lists scenario number:",
value = matrix(c(10, 1, 5), 1, 3, dimnames = list("Scenario 1", c("Periods", "Value 1", "Value 2"))),
cols = list(
extend = FALSE,
names = TRUE,
editableNames = FALSE
),
rows = list(names = TRUE,
delete = TRUE,
extend = TRUE,
delta = 1),
class = "numeric"
),
actionButton("add", "Add scenario")
),
mainPanel(
plotOutput("plot")
)
)
)
server <- function(input, output, session) {
sanitizedMat <- reactiveVal()
observeEvent(input$myMatrixInput, {
if(any(rownames(input$myMatrixInput) == "")){
tmpMatrix <- input$myMatrixInput
rownames(tmpMatrix) <- paste("Scenario", seq_len(nrow(input$myMatrixInput)))
updateMatrixInput(session, inputId = "myMatrixInput", value = tmpMatrix)
}
sanitizedMat(na.omit(input$myMatrixInput))
})
plotData <- reactive({
req(dim(sanitizedMat())[1] >= 1)
lapply(seq_len(nrow(sanitizedMat())),
function(i){
tibble(
Scenario = rownames(sanitizedMat())[i],
X = seq_len(sanitizedMat()[i, 1]),
Y = interpol(sanitizedMat()[i, 1], sanitizedMat()[i, 2:3])
)
}) %>% bind_rows()
})
output$plot <- renderPlot({
req(nrow(plotData()) > 0)
plotData() %>% ggplot() geom_line(aes(
x = X,
y = Y,
colour = as.factor(Scenario)
))
})
}
shinyApp(ui, server)
Initial Answer
There is no need to calulate the numScenarios as they are defined by the dimensions of your matrix. The same applies to the modal you'll add later - just monitor the dimensions of the data to change the plot - no matter which input changes the reactive dataset.
As a general advice I'd recommend working with data.frames in long format instead of a matrix to prepare plots (using e.g. ggplot or plotly). See my answer 
The above Edit works BEAUTIFULLY. Wow. Now the below simple edit of your edit simply pull the periods to interpolate out of the input matrix and back into a single slider input since in the full model this is meant for, modeled periods have to be the same for all input variables. However your 3 column matrix inputs also help me on another matter so THANK YOU. Also, I removed the "Add scenarios" action button since it is no longer needed with the automatically expanding input matrix. I sure learned a lot with this.
Edit of your edit:
ui <- fluidPage(
titlePanel("myMatrixInput"),
sidebarLayout(
sidebarPanel(
sliderInput('periods','Periods to interpolate:',min=2,max=10,value=10),
matrixInput(
"myMatrixInput",
label = "Values to interpolate (myMatrixInput):",
value = matrix(c(1, 5), 1, 2, dimnames = list("Scenario 1", c("Value 1", "Value 2"))),
cols = list(extend = FALSE,
names = TRUE,
editableNames = FALSE),
rows = list(names = TRUE,
delete = TRUE,
extend = TRUE,
delta = 1),
class = "numeric"
),
),
mainPanel(
plotOutput("plot")
)
)
)
server <- function(input, output, session) {
sanitizedMat <- reactiveVal()
observeEvent(input$myMatrixInput, {
if(any(rownames(input$myMatrixInput) == "")){
tmpMatrix <- input$myMatrixInput
rownames(tmpMatrix) <- paste("Scenario", seq_len(nrow(input$myMatrixInput)))
updateMatrixInput(session, inputId = "myMatrixInput", value = tmpMatrix)
}
sanitizedMat(na.omit(input$myMatrixInput))
})
plotData <- reactive({
req(dim(sanitizedMat())[1] >= 1)
lapply(seq_len(nrow(sanitizedMat())),
function(i){
tibble(
Scenario = rownames(sanitizedMat())[i],
X = 1:input$periods,
Y = interpol(input$periods, sanitizedMat()[i, 1:2])
)
}) %>% bind_rows()
})
output$plot <- renderPlot({
req(nrow(plotData()) > 0)
plotData() %>% ggplot() geom_line(aes(
x = X,
y = Y,
colour = as.factor(Scenario)
))
})
}
shinyApp(ui, server)