NOOB - can't figure out how to grab keyboard input

oarnone

Hi all,

New to programming in general. I'm creating a program for school that calculates PI. I have the math working just fine but I want the user to enter a number, then grab this number and pass it to my procedure to perform my calculations. My code is below - I can't get the input from the keyboard to work. About 2/3 of the way down the code you will see a comment saying *** THIS ISN'T WORKING YET **. Not sure what I'm doing wrong.

Any pointers to articles or videos (answer's helpful too ;-) ) would be appreciated.

-- Assignment 7

-- Use this function to perform your initial setup
function setup()  
end

function dothemath (a)

  -- setup variables
  -- first variable - fac - changes from +1 to -1 on each loop
  -- this is so the formula will go number 1 - number 2 + number 3 ....
  fac = 1
  sum = 0

     for i = 1, a do
        term = fac / (2 * i - 1)
        fac = fac * -1 
        sum = sum + term
    end
      pi = (4*sum)  
end

-- when touched the keyboard will display
function touched(touch)
    if touch.state==ENDED then
        showKeyboard()
    end
end

-- if the 'return' key is pressed on the keyboard,
-- hide the keyboard  
function keyboard(key)
    if key == "\n" then
        hideKeyboard()
    end
end


-- This function gets called once every frame
function draw()
    -- This sets a dark background color 
    background(40, 40, 50)

    -- This sets the line thickness
    strokeWidth()

    -- Do your drawing here
     fill(122, 255, 0, 255)
     fontSize(25)
     font("Baskerville-bold")

    -- writes the text for correct counter
    text("How many iterations?",WIDTH*.5,HEIGHT*.8)
    fontSize(20)
    text("(Touch screen to enter number)",WIDTH*.5,HEIGHT*.75)
    fontSize(25)

     -- grab keyboard input, convert to number and pass to function
     -- to do the math
    -- ***** THIS ISN"T WORKING YET *** 
    a = keyboardBuffer()

    if a ~= nil then
      answer = tonumber("a")
      -- this is what I want to do
      -- pass in the keyboard answer, convert it to a number
      -- and calculate the answer

      -- dothemath(answer)

      -- hard code an answer for now to ensure it works
      -- which it does!
      dothemath(4)

      -- print answer to screen
      text("PI is ", WIDTH*.5,HEIGHT*.40)
      text(pi, WIDTH*.5,HEIGHT*.35)  
    end

end

magicskillz

@oarnone

Is this what your looking for?
You can use this for the keyboard and then use the variable str the for calculations

function setup()
    str = ""
end

function draw()
  background(255, 255, 255, 255)

    fontSize(100)
    --text(str,WIDTH/2,HEIGHT/2)  

    buffer = keyboardBuffer()

    fill(255)
    if string.len(buffer)>0 then    -- this line was changed
        fill(0, 255, 188, 255) 
        text(buffer,WIDTH/2,HEIGHT/2)
    else
         fill(0, 255, 188, 255) 
        text(str,WIDTH/2,HEIGHT/2)
    end
end
function touched()
            showKeyboard()
            str=""   
end

function keyboard(key)
    if key == RETURN then
        str = buffer
        hideKeyboard()

        print(str)
    end
end

dave1707

@oarnone The code answer=tonumber("a") should be answer=tonumber(a) . When you call hideKeyboard(), that clears the keyboardBuffer, so you should move it to a variable before the call. Also, when you post code, put 3 ~'s on a line before and after the code so it formats correctly.

dave1707

@oarnone Try making these changes

function keyboard(key)
    if key == "\n" then
        a=keyboardBuffer()       <---- changed
        hideKeyboard()
    end
end

    -- ***** THIS ISN"T WORKING YET *** 
    --a = keyboardBuffer()    <----  changed, commented code

      dothemath(answer)      <-----  changed

dave1707

@oarnone I posted this somewhere on the forum awhile ago, but I couldn't find it, so here it is again. It calculates digits of Pi. Just change the value for digits in the code. I'm not sure what the limit is for digits. Just in case you're interested.

EDIT: I used this link to create the code below.

http://www.pi314.net/eng/goutte.php

-- calculate digits of Pi

function setup()
    local digits=1000  -- number of digits of Pi     <---- change digits
    print("Calculating "..digits.." digits of pi.")
    start=os.clock()
    local pi={}
    local tab={}
    local mf=math.floor
    local size=mf(digits/2)
    local size1=mf(size*6.8)
    local sum
    local carry
    local b
    for i=0,size1 do
        tab[i]=20
    end
    for t=1,size do
        carry=0
        for i=size1,0,-1 do
            sum=tab[i]*100+carry
            b=i*2+1
            tab[i]=sum%b
            carry=mf(sum/b)*i
        end       
        tab[0]=sum%100
        table.insert(pi,mf((sum)/100))
    end
    carry=0
    local x
    for z=size,1,-1 do
        x=pi[z]
        x=x+carry
        if x>99 then
            x=x-100
            carry=1
        else
            carry=0
        end
        pi[z]=string.format("%02d",x)
    end
    pi[1]="3.1"
    print(table.concat(pi))
    print()
    print(digits.." digits of Pi in")
    print(os.clock()-start,"seconds")
end

oarnone

Thanks everyone. I will try this out today.

oarnone

Got it working.. Thanks for the help.