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parameter.text values change randomly when list of parameters is scrolled

edited March 2013 in Bugs Posts: 13

I am creating my first Codea project that uses a number of integer and text parameters for input values. I am using the text input values as numbers by using tonumber() on them in a function. I currently have 8 integer parameters and 4 text parameters, so I have to scroll through the list to make changes. After changing a text parameter, many times, but not all of the time, some or all of the values in the boxes randomly change to match one of the other parameters or back to the initial value. Is there something I should be doing to keep this from happening or is this a bug that needs to be fixed?

I call function EngineCalcs() from inside function (draw) to perform all of my calculations. The program is fairly simple and uses the input values to calculate the ideal thermodynamic values for a gasoline engine based on changes in the parameters.


  • Posts: 835

    Could you put up the code so we can see if we can find anything?

  • Here it is. I am new at this, so it is very possible that I am doing something (multiple things) very wrong.

    --# Main -- Ottomatic supportedOrientations(LANDSCAPE_ANY) -- Use this function to perform your initial setup function setup() p={} V={} --V[2]=25 T={} Wk={net=0,net_engine=0} Q={add=0,rej=0,add_engine=0,rej_engine=0} DeltaU={} DeltaS={} HeatRate={add=0,rej=0} --CV=0 --r_v=0 RPM=3000 Engine_RPM=tostring(RPM) HeatAdd=20000 Heat_Added=tostring(HeatAdd) AF=15 AF_Ratio=tostring(AF)"Today is: %B %d, %Y") parameter.integer("Cylinders", 1, 12, 2 ) parameter.boolean("Two_Stroke", true) parameter.integer("Bore_mm",1.0,200,100) parameter.integer("Stroke_mm",1,200,100) parameter.integer("Ratio_Select",1,2,1) parameter.integer("Compression Ratio",10,150,90) parameter.text("Clearance_Volume_cc","") parameter.integer("T1_degC",0,100,25) parameter.integer("p1_kPa",100,300,100) parameter.text("Engine_RPM",RPM) parameter.integer("Heat_Select",1,3,1) parameter.text("Heat_Added",HeatAdd) parameter.text("AF_Ratio",AF) k=1.399 R=0.287 c_v = R/(k-1) end function EngineCalcs() -- convert input values Bore = Bore_mm/10.0 Stroke = Stroke_mm/10.0 V_D = math.pi/4*Bore^2*Stroke p[1] = p1_kPa T[1] = T1_degC+273.15 if Two_Stroke then StrokeNum=2 else StrokeNum=4 end -- select compression ratio or clearnance volume and calculate V1 if Clearance_Volume_cc ~= "" then CV=tonumber(Clearance_Volume_cc) else CV = 0.1 end if Ratio_Select==1 then r_v = Compression_Ratio/10.0 V[2] = V_D/(r_v-1) V[1] = V[2] + V_D Clearance_Volume_cc = tostring(V[2]) else V[2] = CV V[1] = V[2] + V_D r_v = V[1]/V[2] end -- calculate other volume values V[3] = V[2] V[4] = V[1] V_D_Engine = V_D*Cylinders -- thermal efficincy and engine speed for power calcs Thermal_Eff = 1-(1/r_v^(k-1)) RPM = tonumber(Engine_RPM) if RPM == "" then Speed=0 else Speed = RPM end if Two_Stroke then N=Speed/60 else N=Speed/(2*60) end -- mass of air/fuel mixture m = p[1]*(V[1]/100)/(R*T[1]) -- calculate p2 and T2 p[2] = p[1]*r_v^k T[2] = p[2]*(V[2]/100^3)/(m*R) -- calculate heat added, T3, and p3 if AF_Ratio=="" then AF=0 else AF=tonumber(AF_Ratio) end if Heat_Added=="" then HeatAdd=0 else HeatAdd=tonumber(Heat_Added) end if Heat_Select==1 then Q.add = HeatAdd*m/(AF+1) elseif Heat_Select==2 then Q.add = HeatAdd*m else Q.add = HeatAdd end T[3] = T[2]+Q.add/(m*c_v) p[3] = p[2]*T[3]/T[2] -- calculate p4 and T4 p[4] = p[3]*r_v^-k T[4] = p[3]*(V[3]/100^3)/(m*R) -- calculate work from 1-2 and 3-4 Wk[12] = 1/(1-k)*(p[2]*V[2]-p[1]*T[1]) Wk[34] = 1/(1-k)*(p[4]*V[4]-p[3]*T[3]) -- internal energy changes DeltaU[12] = -Wk[12] DeltaU[23] = Q.add DeltaU[34] = -Wk[34] DeltaU[41] = Q.rej -- entropy changes DeltaS[23] = m*c_v*math.log(T[3]/T[2]) DeltaS[41] = m*c_v*math.log(T[1]/T[4]) -- net work, net heat, power, and heat rate = Wk[12]+Wk[34] Wk.net_engine =*Cylinders Power = Wk.net_engine*N = Q.add+Q.rej Q.add_engine = Q.add*Cylinders Q.rej_engine = Q.rej*Cylinders HeatRate.add = Q.add_engine*N HeatRate.rej = Q.rej_engine*N end -- This function gets called once every frame function draw() EngineCalcs() -- This sets a dark background color background(210, 210, 215, 255) -- This sets the line thickness strokeWidth(4) -- Do your drawing here stroke(0) line(0,HEIGHT-150,WIDTH,HEIGHT-150) displayMode(STANDARD) textMode(CENTER) fill(0) font("Courier-Bold") textWrapWidth(800) fontSize(24) text("The",WIDTH/2,HEIGHT-25) fontSize(100) text("OTTO",WIDTH/2.5,HEIGHT-75) fontSize(32) text("...matic",2*WIDTH/3,HEIGHT-120) textMode(CORNER) fontSize(12) text(tostring(t),20,HEIGHT-148) fontSize(24) text("Engine Specifications:",10,HEIGHT-190) fontSize(14) font("HelveticaNeue") text("Adjust sliders to change engine values.",400,HEIGHT-175) text("Hide keyboard after typing vales.",400,HEIGHT-190) font("Courier") fontSize(16) text("Bore: "..string.format("%4.1f",Bore).."cm",40,HEIGHT-220) text("Stroke: "..string.format("%4.1f",Stroke).."cm",180,HEIGHT-220) text(Cylinders.."-Cylinder",360,HEIGHT-220) text(StrokeNum.."-Stroke",500,HEIGHT-220) if Ratio_Select==1 then font("Courier-Oblique") text("Compression Ratio Option Selected",40,HEIGHT-250) font("Courier") text(string.format("%.1f",r_v)..":1 Compression Ratio",60,HEIGHT-280) text("Clearance Volume: "..string.format("%4.1f",V[2]).."cc",340,HEIGHT-280) else font("Courier-Oblique") text("Clearance Volume Option Selected",40,HEIGHT-250) font("Courier") text("Clearance Volume: "..string.format("%4.1f",V[2]).."cc",60,HEIGHT-280) text(string.format("%4.1f",r_v)..":1 Compression Ratio",340,HEIGHT-280) end if Heat_Select==1 then font("Courier-Oblique") text("Fuel Heating Value Option Selected",40,HEIGHT-310) font("Courier") text("Fuel Heating Value: "..HeatAdd.."kJ/(kg of fuel)",60,HEIGHT-340) text("Air Fuel Ratio: "..AF..":1",500,HEIGHT-340) elseif Heat_Select==2 then font("Courier-Oblique") text("Specific Heat Added Option Selected",40,HEIGHT-310) font("Courier") text("Specific Heat Added: "..HeatAdd.."kJ/kg",60,HEIGHT-340) else font("Courier-Oblique") text("Total Heat Added per Cylinder Option Selected",40,HEIGHT-310) font("Courier") text("Total Heat Added per Cylinder: "..HeatAdd.."kJ",60,HEIGHT-340) end --text(RPM.." RPM",40,HEIGHT-310) line(0,HEIGHT-350,WIDTH,HEIGHT-350) fontSize(24) font("Courier-Bold") text("Results:",10,HEIGHT-390) fontSize(16) font("Courier") text("Cylinder Displacement Volume: "..string.format("%.1f cc",V_D),20,HEIGHT-420) text("Thermal Efficiency: "..string.format("%.1f%%",Thermal_Eff*100),20,HEIGHT-450) text("Engine Speed: "..N.." cyles/second",20,HEIGHT-480) end function keyboard(key) if CCActiveTextBox then CCActiveTextBox:acceptKey(key) end end function touched(touch) -- Codea does not automatically call this method end
  • dave1707dave1707 Mod
    Posts: 9,586

    Not sure if this is a problem or not, but when I change the Engine_RPM, I get an error. I changed the line to    if RPM == "" or RPM==nil then Speed=0 else Speed = RPM end and that stopped the error.

  • Thanks. I just fixed that a couple of other cases that were similar. The text parameters change after scrolling through the parameters list one or more times. It seems to happen more often when the keyboard is still showing after making a change, but also happens when the keyboard is hidden.

  • dave1707dave1707 Mod
    Posts: 9,586

    I noticed that the text parameters change values even if they don't get changed originally. Just scroll the parameters up and down and they change. I also saw where the values went blank and stayed that way until I restarted the program.

  • Exactly. Apparently you don't know why either. Good to see that it is not just me though.

  • SimeonSimeon Admin Mod
    Posts: 5,714

    Thanks for the bug report and example code. Will fix.

  • Great. I look forward to it. Right now I just need to keep an eye on the results to make sure none of the inputs changed on me. Not a problem, this is to show my students how modeling the Otto thermo cycle could be done.

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