How to draw a line between two given points in R with plotly?

Question

I'm trying to draw some kind of trend line using highs and lows from cryptocurrencies (CC) prices. First libraries I'm using:

library(tidyverse)
library(reshape2)
library(lubridate)
library(TTR)
library(binancer)
library(plotly)

Since I choose among many CC, I'm using next scheme to achieve some kind of automation. For this example, I use Bitcoin (BTC). The following code will retrieve data for Bitcoin for 4 hours timeframe. I set "horas" to 900 in order to get 225 observations:

nombre <- "BTC"
tiempo <- "4h"
horas <- 900

data <- binance_klines(paste0(nombre,"USDT"), interval = paste0(tiempo), 
    start_time=Sys.time()-hours(paste0(as.numeric(horas))), end_time=Sys.time())%>%
    select(open_time, open, high, low, close, volume, trades)%>%
    rename(time=1)

Next I get lows and highs to use this data for drawing the lines I want. As you can see, I choose exactly two points for either highs and lows:

lows <- arrange(data, low)%>%
    slice(c(which.min(low), which.max(low)))%>%
    arrange(time)

highs <- arrange(data, high)%>%
    slice(c(which.max(high), which.min(high)))%>%
    arrange(time)

And I also add some simple moving averages (SMA). My sma database is the source for my plot:

data%>%
    mutate(SMA_5= SMA(close, 5), SMA_10= SMA(close,10), SMA_20= SMA(close,20)) -> sma

I'm trying to use add_segments to draw the line I want for lows (if this works I'll use same code for highs) but I got some error:

sma %>% plot_ly(x = ~time, type="candlestick",
                       open = ~open, close = ~close,
                       high = ~high, low = ~low) %>%
    add_lines(x = ~time, y= ~SMA_5,  line = list(color = "gold", width = 2), inherit = F,
                name = "SMA 5", showlegend=T)%>%
    add_lines(x = ~time, y= ~SMA_10,  line = list(color = "deeppink", width = 2), inherit = F,
                name = "SMA 10", showlegend=T)%>%
    add_lines(x = ~time, y= ~SMA_20,  line = list(color = "purple", width = 2), inherit = F,
                name = "SMA 20", showlegend=T)%>%
    add_segments(
                x = ~lows[1,1], xend = ~lows[2,1], 
                y = ~lows[1,4], yend = ~lows[2,4], color="black")%>%
    plotly::layout(title = paste0(nombre, " Simple Moving Average, ", tiempo),
        xaxis= list(title="Time", rangeslider = list(visible = F)), yaxis = list(title = "Price"),
        sliders=list(visible=F)) -> sma_plot

sma_plot

Error in `*tmp*`[[jj]] : subscript out of bounds 

Any idea on what I'm doing wrong? Any feedback will be highly appreciated.

Answer 1

If you are trying to draw a line between the two coordinates, just use the same pattern you used with the other lines.

add_lines(inherit = F, data = lows, x = ~time, y = ~low, 
          name = "Lows, line = list(color = "black"))