Package the code into functions [closed]

Question

I use

Clear["Global`*"];
(*=== 数据点  ===*)
bmiData = {17.53231562, 15.53238528, 17.26137457, 15.6088015, 
   15.20589021, 14.51292182, 14.75645275, 13.83305466, 15.69560048, 
   16.86902697, 18.0721242, 15.14403292, 17.44614778, 13.850415510, 
   18.32280354, 20.1631851, 18.59012493, 17.45527841, 18.58163511, 
   14.55731214, 15.40417624, 15.18792708, 15.62461325, 15.22882797, 
   15.02163115, 21.45492911, 20.89541272, 18.38647653, 29.34474265, 
   21.08535689, 22.02071132, 16.52876307, 18.38228254, 22.14403633, 
   19.2399927, 22.82261329, 26.10290031, 20.6759324, 22.34966855, 
   24.02533886};
fhlData = {1750, 2000, 2750, 2500, 2750, 2000, 2750, 1500, 2500, 2250,
    3000, 1250, 2750, 1750, 2250, 1750, 2000, 2250, 2750, 2000, 1750, 
   2250, 2750, 2500, 2000, 2772, 3458, 2065, 4208, 4579, 5300, 2811, 
   2563, 4075, 3762, 4781, 3919, 4357, 3839, 3770};

(*=== 基函数 ===*)
basisfun[n_] := Table[x^i, {i, 0, n}]

(*=== 数据点点图  ===*)
bmiListPlt = 
  ListPlot[bmiData, PlotStyle -> {Red}, PlotMarkers -> "OpenMarkers"];
fhlListPlt = 
  ListPlot[fhlData, PlotStyle -> {Red}, PlotMarkers -> "OpenMarkers"];

(*=== 数据点拟合 ===*)
bmifit = Fit[bmiData, basisfun@7, x];
fhlfit = Fit[fhlData, basisfun@7, x];

(*=== 拟合图像 ===*)
bmiFitPlt = Plot[
   bmifit,
   {x, 0, Length@bmiData + 1},
   PlotRange -> All
   ];

fhlFitPlt = Plot[
   fhlfit,
   {x, 0, Length@fhlData + 1},
   PlotRange -> All
   ];

(*=== 多项式拟合拟合和点图 ===*)
bmishow = Show[bmiFitPlt, bmiListPlt]
fhlshow = Show[fhlFitPlt, fhlListPlt]

get this

as you can see ,I had to go through the following steps

• get point data
• Constructing polynomial function
• Point plotted on a graph
• Do the fitting and draw the fitting curve
• Plot the fitting curve and data points on a graph

As you can see, I have two sets of data here, so I copy and paste a lot, in fact, I have many sets of data, so copying and pasting over and over again is obviously not a good idea.

Is there any way to package all of this into a function?

For example, if I input the data of the points and the number of fits I can draw the fit curve and the point graph directly

Answer 1

Use Module

$Version

(* "13.1.0 for Mac OS X x86 (64-bit) (June 16, 2022)" *)

Clear["Global`*"]

fit[data_?VectorQ, n : _Integer?NonNegative : 7, opts___] :=
 Module[
  {func = Fit[data, x^Range[0, n], x]},
  Show[
   Plot[Tooltip[func],
    {x, 0, Length@data + 1}],
   ListPlot[data,
    PlotStyle -> Red, 
    PlotMarkers -> "OpenMarkers"],
   FilterRules[{opts}, Options[Plot]], 
   Frame -> True,
   Axes -> False,
   PlotRange -> All]]

Examples,

bmiData = {17.53231562, 15.53238528, 17.26137457, 15.6088015, 15.20589021, 
   14.51292182, 14.75645275, 13.83305466, 15.69560048, 16.86902697, 
   18.0721242, 15.14403292, 17.44614778, 13.850415510, 18.32280354, 
   20.1631851, 18.59012493, 17.45527841, 18.58163511, 14.55731214, 
   15.40417624, 15.18792708, 15.62461325, 15.22882797, 15.02163115, 
   21.45492911, 20.89541272, 18.38647653, 29.34474265, 21.08535689, 
   22.02071132, 16.52876307, 18.38228254, 22.14403633, 19.2399927, 
   22.82261329, 26.10290031, 20.6759324, 22.34966855, 24.02533886};

fit[bmiData, PlotLabel -> "bmiData"]

fhlData = {1750, 2000, 2750, 2500, 2750, 2000, 2750, 1500, 2500, 2250, 3000, 
   1250, 2750, 1750, 2250, 1750, 2000, 2250, 2750, 2000, 1750, 2250, 2750, 
   2500, 2000, 2772, 3458, 2065, 4208, 4579, 5300, 2811, 2563, 4075, 3762, 
   4781, 3919, 4357, 3839, 3770};

fit[fhlData, PlotLabel -> "fhlData"]

Answer 2

OK, since OP fails to understand the document and tutorial linked in the comment, I'll write an answer just to prove my statement:

200 lines of code are not more complicated than 2 lines of code for defining a function. All you need is just () and ;. Oh, you already have ;s, so you just need a pair of ().

函数[bmiData_, n_] := (
  (*===数据点点图===*)
  bmiListPlt = ListPlot[bmiData, PlotStyle -> {Red}, PlotMarkers -> "OpenMarkers"];
  
  
  (*===数据点拟合===*)
  bmifit = Fit[bmiData, basisfun@n, x];
  
  (*===拟合图像===*)
  bmiFitPlt = Plot[bmifit, {x, 0, Length@bmiData + 1}, PlotRange -> All];
  
  
  (*===多项式拟合拟合和点图===*)
  bmishow = Show[bmiFitPlt, bmiListPlt]
  )

Definition of basisfun is the same as yours so omitted in this answer. Variable names are not modified, and are not localized with Module, etc., these aren't good habits of course. I don't modify them because they're not necessary. As mentioned above, all you need for defining a working function is just a pair of (). And it's my personal belief that a beginner should never try to pretend to be professional with Module, etc. if he doesn't really understand its usage.

Then the function can be used like

函数[bmiData, 7]

函数[fhlData, 7]

Now do you still feel it more complicated than the example in document?: