Dear Bert,
Thank you for your kind reply.
That is fine, I appreciate your feedback anyway.
Have a great day/night.
Best,
Paul
El mié, 20 abr 2022 a las 23:31, Bert Gunter (<bgunter.4...@gmail.com>)
escribió:
> I believe I gave you sufficient information (the vector of dice roll
> results would replace 1:36 in my example). Furthermore, this sounds
> like homework, which we try not to do here. But even if it is not, I
> expect you to fill in the details based on what I have provided. If I
> have misunderstood your query, I am sorry: I am too lazy to go through
> your long explanation. If I have understood correctly, perhaps others
> will be kinder and provide you the missing details that I did not.
>
>
> Bert Gunter
>
> On Wed, Apr 20, 2022 at 9:02 PM Paul Bernal <paulberna...@gmail.com>
> wrote:
> >
> > Dear friend Bert,
> >
> > Thank you so much for your kind reply. The first thing I need to do is
> to simulate dice rolls, say 120 times.
> >
> > I want to populate an m by 12 dataframe with the results of each dice
> roll. For example, the result from dice roll #1 would need to go on row 1,
> column1, the result from dice roll #2 would have to go in row 1 column 2,
> and so on.
> >
> > The reason why I want to store those results in a dataframe is to be
> able to perform some other calculations afterwards.
> >
> > This is for a project I am doing.
> >
> > So this is the situation:
> > You and five friends – a total of six people – plan to meet once per
> month to have dinner together, with one of you choosing the restaurant each
> month. Rather than scheduling the entire year in advance, you decide to
> make it interesting: each month a single six-sided die will be rolled to
> determine which of you gets to choose the restaurant that month. How likely
> is it that everyone will have a chance to eat at their own favorite
> restaurant? That is, what is the probability p that over the next 12
> months, each of you will have had at least one opportunity to choose where
> to eat?
> >
> > This is what I am asked to do:
> > Write a program to estimate the desired probability p via simulation.
> The program should input a sequence of positive integer number of trials to
> simulate using the language's pseudorandom number generator and calculate
> the corresponding fractions of simulated trials that are “successful"
> (i.e., all 6 parties get at least one opportunity to choose where to eat.
> Alice, Bob, Charley, Fred, Ellen, Don, Don, Don, Don, Alice, Charley, Bob
> is a successful trial. Alice, Bob, Charley, Ellen, Don, Don, Don, Don,
> Ellen, Alice, Charley, Bob is not a successful trial since Fred does not
> get to choose.)
> > Turn in a set of 10 trials showing each roll of the dice to show
> correctness. Label the out-comes. Keep in mind that a single trial requires
> rolling the die twelve times. Calculate and print the average probability p
> for the set. Please refer to your friends by name.
> >
> > For this reason, I am trying to simulate the n trials, and then populate
> a table with the results from the trials. I have to simulate a dice roll
> dice for each month and for each row. Rows would be equivalent to years,
> and then columns would be equivalent to the month of a particular year.
> >
> > Once I store the results in a dataframe, everything is much easier.
> >
> > I installed package dice and performed simulations by doing:
> > #declaring variables:
> > #1)dice_rolls which is the number of times the dice will be rolled
> > #2)num_dice which is the number of dice that will be rolled each time
> > #3)dice_sides which is the number of sides of the dice
> > #function dice will take each one of these variables as its parameter to
> perform the simulation
> > dice_rolls = 120
> > num_dice = 1
> > dice_sides = 6
> >
> > #performing simulation
> > dice_simul = dice(rolls = dice_rolls, ndice = num_dice, sides =
> dice_sides, plot.it = TRUE)
> >
> > I tried the following, but did not work as expected:
> >
> > for (i in 1:nrow(dice_simul)){
> > for(j in 1:ncol(prob_frame)){
> > for(k in 1:nrow(prob_frame)){
> > prob_frame[k,j] = dice_simul[i,1]
> > }
> > }
> > }
> >
> > I apologize for the long explanation.
> >
> > Best regards,
> >
> > Paul
> >
> >
> > El mié, 20 abr 2022 a las 22:47, Bert Gunter (<bgunter.4...@gmail.com>)
> escribió:
> >>
> >> If I understand you correctly, it's simple.
> >> Matrices in R are vectors with a dimension attribute. By default, they
> >> are populated column by column. Use 'byrow = TRUE to populate by row
> >> instead. For example:
> >>
> >> > matrix (1:36, ncol = 12, byrow = TRUE)
> >> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
> >> [1,] 1 2 3 4 5 6 7 8 9 10 11 12
> >> [2,] 13 14 15 16 17 18 19 20 21 22 23 24
> >> [3,] 25 26 27 28 29 30 31 32 33 34 35 36
> >>
> >> I leave it to you to use the 'dimnames' argument of ?matrix to give
> >> names to the column and then subsequently convert to a data frame if
> >> you like.
> >>
> >> Bert Gunter
> >>
> >> "The trouble with having an open mind is that people keep coming along
> >> and sticking things into it."
> >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
> >>
> >> On Wed, Apr 20, 2022 at 8:38 PM Paul Bernal <paulberna...@gmail.com>
> wrote:
> >> >
> >> > Dear friends,
> >> >
> >> > Hope you are doing well. I need to simulate a 1 dice roll for each
> one of
> >> > the twelve months of the year and perform 100 trials, so I thought of
> >> > constructing a dataframe with twelve columns and 100 rows the
> following way:
> >> >
> >> > num_rows = 100
> >> >
> >> > prob_frame <- data.frame(matrix(NA, nrow = num_rows, ncol = 12))
> >> >
> colnames(prob_frame)<-c("January","February","March","April","May","June","July","August","September","October","November","December")
> >> >
> >> > Now, using the dice package, I can simulate n number of dice rolls as
> >> > follows:
> >> > #performing simulation
> >> > dice_simul = dice(rolls = dice_rolls, ndice = num_dice, sides =
> dice_sides,
> >> > plot.it = TRUE)
> >> >
> >> > What I would like to do is to populate each column and row with the
> results
> >> > of dice_simul.
> >> >
> >> > Let me show you the structure of dice_simul:
> >> > > str(dice_simul)
> >> > Classes ‘dice’ and 'data.frame': 100 obs. of 1 variable:
> >> > $ Red: int 2 2 1 2 5 4 4 6 1 4 ...
> >> > > dput(dice_simul)
> >> > structure(list(Red = c(2L, 2L, 1L, 2L, 5L, 4L, 4L, 6L, 1L, 4L,
> >> > 4L, 2L, 6L, 2L, 2L, 1L, 3L, 6L, 1L, 5L, 5L, 5L, 3L, 4L, 2L, 6L,
> >> > 4L, 6L, 6L, 2L, 1L, 2L, 2L, 6L, 4L, 2L, 3L, 5L, 6L, 6L, 4L, 5L,
> >> > 4L, 6L, 6L, 3L, 4L, 1L, 5L, 3L, 3L, 5L, 3L, 4L, 1L, 3L, 3L, 2L,
> >> > 4L, 1L, 2L, 1L, 6L, 3L, 5L, 5L, 3L, 4L, 4L, 5L, 4L, 1L, 5L, 3L,
> >> > 4L, 4L, 3L, 6L, 5L, 2L, 4L, 1L, 1L, 6L, 4L, 3L, 6L, 5L, 6L, 2L,
> >> > 6L, 1L, 6L, 6L, 4L, 3L, 4L, 2L, 1L, 5L)), class = c("dice",
> "data.frame"
> >> > ), row.names = c(NA, -100L))
> >> >
> >> > For example, the first number of dice_simul should go to row 1 for
> January,
> >> > the second number of dice_simul should go to row 1 for February, ...
> the
> >> > twelveth number of dice_simul should go to row 1 for December, the
> 13th
> >> > number should go to row 2 for january, and so on.
> >> >
> >> > This is what I tried to do but doesn´t work they way I want to:
> >> >
> >> > #1)dice_rolls which is the number of times the dice will be rolled
> >> > #2)num_dice which is the number of dice that will be rolled each time
> >> > #3)dice_sides which is the number of sides of the dice
> >> > #function dice will take each one of these variables as its parameter
> to
> >> > perform the simulation
> >> > dice_rolls = 100
> >> > num_dice = 1
> >> > dice_sides = 6
> >> >
> >> > #performing simulation
> >> > dice_simul = dice(rolls = dice_rolls, ndice = num_dice, sides =
> dice_sides,
> >> > plot.it = TRUE)
> >> >
> >> > num_rows = 100
> >> >
> >> > prob_frame <- data.frame(matrix(NA, nrow = num_rows, ncol = 12))
> >> > colnames(prob_frame) <-
> >> >
> c("January","February","March","April","May","June","July","August","September","October","November","December")
> >> >
> >> >
> >> > for (j in 1:12){
> >> > for (i in 1:num_rows){
> >> > prob_frame[i,j]=dice_simul[i,1]
> >> > }
> >> > }
> >> > I basically want to populate the twelve months for the first row,
> then the
> >> > twelve months for the second row, and so on, until I get to populate
> the
> >> > twelve months for the last row sequentially.
> >> >
> >> > How could I accomplish this?
> >> >
> >> > Any help and/or guidance will be greatly appreciated.
> >> >
> >> > Best regards,
> >> > Paul
> >> >
> >> > [[alternative HTML version deleted]]
> >> >
> >> > ______________________________________________
> >> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> > https://stat.ethz.ch/mailman/listinfo/r-help
> >> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> >> > and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
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