Averaging / ''Smoothing'' a 2 dimensional array?

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Socoder -> Blitz -> Averaging / ''Smoothing'' a 2 dimensional array?
Wed, 23 Nov 2011, 01:10
Mog	Hey guys, Brains really off and i can't remember for the life of me how to smooth out the data in an array by averaging it all together, any tips / pointers? -=-=- I am Busy Mongoose - My Website Dev PC: AMD 8150-FX, 16gb Ram, GeForce GTX 680 2gb Current Project: Pyroxene
Wed, 23 Nov 2011, 01:15
Jayenkai	avg=0 for x=1 to items avg=avg+item[x] next avg=avg/items --v Bulk simple average for all.. smooth=3 for x=1 to items-smooth avg=0 for sm=1 to smooth avg=avg+item[(x+sm)-1] next item[x]=avg/smooth next --v average clumps! -=-=- ''Load, Next List!''
Wed, 23 Nov 2011, 01:41
spinal	I'd go with the 'clumps' idea, but only two values at a time. -=-=- Check out my excellent homepage!
Sat, 26 Nov 2011, 11:56
Teasy	; for 1 user ; setup (for demo) Const screen_width = 120;80 Const screen_height = 60 Graphics screen_width,screen_height , 0,3 SetBuffer BackBuffer() SetFont LoadFont( "Small Fonts" , 10 ) ; graph/posting type Global test_graph_type = 2 ; smoothing/algorithm type Global smoothingtype = 1 ; bar overlay Global showbar = False .restart Const number_of_weeks = 7;12 Const days_per_week = 7 Const number_of_days = number_of_weeks * days_per_week Dim posts_per_day( number_of_days ) ; test graph SeedRnd MilliSecs() Const test_max_posts_per_day = 20 ; average Local num Select test_graph_type ; smooth forum usage (from little to a lot) Case 1 Color 64,96,128 Text 0,0 , "1. Steady posting" For num = 1 To number_of_days ; sine (low first, high second) as base Local sinval# = (1-Sin(num360/number_of_days))/2. ; with some random variation Local rndval# = sinval Rnd(0.5,1.5) posts_per_day( num ) = test_max_posts_per_day * rndval Next ; erratic forum usage (sporadic peaks) Case 2 Color 64,96,128 Text 0,0 , "2. Erratic posting" Local value For num = 1 To number_of_days If Rand(1,100) <= 10 value = Rand( 1,test_max_posts_per_day ) Else value = 0 End If posts_per_day( num ) = value Next ; have at least 1 point in the graph with max value posts_per_day( Rand(1,number_of_days) ) = test_max_posts_per_day ; linear graph from low to high Case 3 Color 64,96,128 Text 0,0 , "3. Linear graph L-R" For num = 1 To number_of_days posts_per_day( num ) = numtest_max_posts_per_day/number_of_days Next ; linear graph from high to low Case 4 Color 64,96,128 Text 0,0 , "4. Linear graph R-L" For num = 1 To number_of_days posts_per_day( number_of_days-num+1 ) = numtest_max_posts_per_day/number_of_days Next ; single (max) point in the center Case 5 Text 0,0 , "5. One spamday" ;posts_per_day( number_of_days/2 ) = test_max_posts_per_day posts_per_day( Rand(1,number_of_days) ) = test_max_posts_per_day End Select ; debugging graph (right side of screen) ;Local num Local x,y For num = 1 To number_of_days x = screen_width-1 - posts_per_day( num ) y = num-1 Color 128,96,64 Rect x,y , posts_per_day( num ),1 Color 255,192,128 Plot x,y Next ; scale the points up for major improve in accuracy/smoothing Const points_scale_value# = 10 ;Local num DebugLog "" DebugLog "" For num = 1 To number_of_days DebugLog "num "+num+" val "+posts_per_day(num)+" scl "+posts_per_day(num)points_scale_value posts_per_day( num ) = posts_per_day( num ) points_scale_value Next ; add smoothing (optional) Select smoothingtype Case 0 Color 64,96,128 Text 0,10 , "0. No smoothing" Goto nosmooth Case 1 Goto smooth1 ; block smooth (advanced) Case 2 Goto smooth2 ; incremental smooth (lame) Case 3 Goto smooth3 ; curve smooth (lame) Case 4 Goto smooth4 ; reverse double smooth Case 5 Goto smooth5 ; dynamic interpolation (advanced) End Select ; average block smoothing with interpolation .smooth1 Color 64,96,128 Text 0,10 , "1. Block smoothing" ApplyBlockSmooth Const smoothingblocks = 7 ; divide graph in even segments Function ApplyBlockSmooth() ; - calc average of segments Local averagepoints[ smoothingblocks ] ; posts per day, average per segment Local count,total Local newsegment Local oldsegment Local num For num = 1 To number_of_days count = count + 1 total = total + posts_per_day( num ) ; find segment for this point/day newsegment = (num-1)smoothingblocks/number_of_days ; new segment or last point/day If newsegment > oldsegment Or num = number_of_days ; calculate old average and store point If oldsegment > -1 averagepoints[ oldsegment ] = total/count End If ; update segment and reset average oldsegment = newsegment count = 0 total = 0 End If Next ; - pad start/end of graph with first/last average Local smoothinginterval = number_of_days / smoothingblocks For num = 1 To smoothinginterval posts_per_day( num ) = averagepoints[ 0 ] posts_per_day( number_of_days-num+1 ) = averagepoints[ smoothingblocks-1 ] Next ; - apply interpolation to average points, and overwrite graph Local newvalue Local oldvalue Local segment ;Local oldsegment oldsegment = -1 Local oldsegmentpoint Local newsegmentpoint Local segmentsize Local deltavalue# For num = 1 To number_of_days ; find segment for this point/day segment = (num-1)smoothingblocks/number_of_days If segment > oldsegment oldsegment = segment oldsegmentpoint = num newsegmentpoint = (segment+1)number_of_days/smoothingblocks segmentsize = newsegmentpoint-oldsegmentpoint End If ; find previous (current) and next average value oldvalue = averagepoints[ segment ] newvalue = averagepoints[ segment+1 ] ; calculate position (delta) in interpolated 'line' deltavalue = Float ( num - oldsegmentpoint ) / segmentsize ; shift by half a segment (center align) Local index = num+smoothinginterval/2 posts_per_day( index ) = oldvalue + (newvalue-oldvalue) deltavalue If posts_per_day( index ) < 0 posts_per_day( index ) = 0 End If ; average cuts off sides of graph If segment = smoothingblocks-1 Exit End If Next End Function Goto nosmooth ; incremental average smoothing .smooth2 Color 64,96,128 Text 0,10 , "2. Incremental smoothing" Local total total = 0 For num = 1 To number_of_days total = total + posts_per_day( num ) ; smooth current value with total average (incremental) ;posts_per_day( num ) = ( posts_per_day( num ) + total/num ) / 2 ;posts_per_day( num ) = total/num DebugLog "num "+num+" val "+posts_per_day(num)+" avg "+total/num+" tot "+total Next Goto nosmooth ; average smoothing with a curve .smooth3 Color 64,96,128 Text 0,10 , "3. Curve smoothing" ;Local total total = 0 Local prevvalue For num = 1 To number_of_days If posts_per_day( num ) <= 0 total = total / 1.11111 If total < 0 total = 0 End If ElseIf posts_per_day( num ) >= prevvalue total = ( total + posts_per_day( num ) ) / 2 ;Else ;total = posts_per_day( num ) End If prevvalue = posts_per_day( num ) ; smooth current value with total average (incremental) ;posts_per_day( num ) = ( posts_per_day( num ) + total/num ) / 2 ;posts_per_day( num ) = total/num ;posts_per_day( num ) = ( posts_per_day( num ) + total ) / 2 posts_per_day( num ) = total Next Goto nosmooth ; double (reverse) curve smoothing .smooth4 Color 64,96,128 Text 0,10 , "4. Reverse smoothing" ; convert points to separate array Local ArrayBank[ArrayBankLimit] ClearArrayBank ArrayBank ;Local num For num = 1 To number_of_days ArrayBank[num] = posts_per_day( num ) Next ; do the smooth SmoothArrayBank ArrayBank , 1,number_of_days , 1.11111 ; convert separate array back to points For num = 1 To number_of_days posts_per_day( num ) = ArrayBank[num] Next Goto nosmooth .smooth5 Color 64,96,128 Text 0,10 , "5. Dynamic smoothing" ; convert points to separate array ;Local ArrayBank[ArrayBankLimit] ClearArrayBank ArrayBank ;Local num For num = 1 To number_of_days ArrayBank[num] = posts_per_day( num ) Next ; do the smooth DynamicSmoothArrayBank ArrayBank , 1,number_of_days ; convert separate array back to points For num = 1 To number_of_days posts_per_day( num ) = ArrayBank[num] Next Goto nosmooth .nosmooth ; find peak value ; - if all posts per day are 0 ; don't render/draw (and/or delete image) Local peak = -1 ;Local num For num = 1 To number_of_days If posts_per_day( num ) > peak peak = posts_per_day( num ) End If Next If peak = 0 ;End End If ;Text 0,screen_height-10 , "Peak: "+peak ;Local textstring$ = "Peak: "+peak ;Text screen_width-StringWidth(textstring),screen_height-FontHeight()2 , textstring Text 0,screen_height-FontHeight()2 , "Peak: "+peak ; prepare render Const image_width = 48 Const image_height = 15 ; prepare overlay (for gradient) Local overlayimage = CreateImage( image_width,image_height ) ; render graph Local graphimage = CreateImage( image_width,image_height ) MaskImage graphimage , 255,0,255 SetBuffer ImageBuffer( graphimage ) ;Local num Local h ;Local x,y Color 255,0,255 ; - allow visual update even when all values are 0 If peak = 0 Then peak = 1 For num = 1 To number_of_days h = 1+(posts_per_day(num)+0)image_height/peak x = (num-1)image_width/number_of_days y = image_height-h Rect x,y , 1,h Next ; render gradient overlay Local gradientimage = LoadImage( "activitybar-gradient1a.png" ) SetBuffer ImageBuffer( overlayimage ) DrawBlock gradientimage , 0,0 DrawImage graphimage , 0,0 ; show/demo with gradient Local backimage = LoadImage( "activitybar1a.png" ) SetBuffer BackBuffer() ;Local x,y x = screen_width/2-ImageWidth(backimage)/2 y = screen_height/2-ImageHeight(backimage)/2 Local xo = x + 8 Color 255,255,255 Rect xo,y , ImageWidth(overlayimage),ImageHeight(overlayimage) , False Color 64,96,128 Text 0,GraphicsHeight()-FontHeight() , "Up Down Space Enter Esc" DrawImage overlayimage , xo,y If showbar DrawImage backimage , x,y End If Flip FlushKeys WaitKey Cls If Not KeyHit(1) If KeyHit(200) test_graph_type=test_graph_type+1 If test_graph_type>5 test_graph_type=1 End If End If If KeyHit(208) smoothingtype=smoothingtype+1 If smoothingtype>5 smoothingtype=0 End If End If If KeyHit(28) showbar=Not showbar End If Goto restart End If End ;------------------------------------------------------------------------------- Const ArrayBankLimit = 1024 Function SmoothArrayBank( ArrayBank[ArrayBankLimit] , Offset,Size , divisor#=1 ) Local times Local total Local num Local prevvalue Local endpoint = Offset+Size For times = 1 To 2 ReverseArrayBank ArrayBank , Offset,Size total = 0 prevvalue = 0 For num = Offset To endpoint If ArrayBank[num] <= 0 total = total / divisor If total < 0 total = 0 End If ElseIf ArrayBank[num] >= prevvalue total = ( total + ArrayBank[num] ) / 2 End If prevvalue = ArrayBank[num] ArrayBank[num] = total Next Next End Function Function ReverseArrayBank( ArrayBank[ArrayBankLimit] , Offset,Size ) Local swap Local num Local reversenum Local endpoint = Offset+Size For num = Offset To endpoint reversenum = endpoint-(num-Offset) swap = ArrayBank[num] ArrayBank[num] = ArrayBank[reversenum] ArrayBank[reversenum] = swap ; only half of numbers needed If num >= Offset+Size/2 Exit End If Next End Function Function ClearArrayBank( ArrayBank[ArrayBankLimit] , Offset=0,Size=ArrayBankLimit , ClearValue=0 ) Local num Local endpoint = Offset+Size For num = Offset To endpoint ArrayBank[num] = ClearValue Next End Function Function FindNextNonZero( ArrayBank[ArrayBankLimit] , Offset ) Local num For num = Offset To ArrayBankLimit If ArrayBank[num] Return num End If Next Return ArrayBankLimit+1 End Function ; incomplete / unimplemented Function DynamicSmoothArrayBank( ArrayBank[ArrayBankLimit] , Offset,Size ) Local num,nextnum Local endpoint = Offset+Size Local endslope = True num = FindNextNonZero( ArrayBank , Offset ) If num > endpoint Return End If ; pad (slope up) leading section with first value found in a slope ; - only if not a perfect fit (first point in graph) If num > Offset SlopeArrayBank ArrayBank , Offset,num-Offset , 0,ArrayBank[num] End If ; start looking for next points Repeat nextnum = FindNextNonZero( ArrayBank , num+1 ) If nextnum > endpoint Exit ElseIf nextnum = endpoint ; no end slope needed (perfect fit) endslope = False End If ; and smooth the space between points SlopeArrayBank ArrayBank , num,nextnum-num , ArrayBank[num],ArrayBank[nextnum] num = nextnum Until num = endpoint ; the trailing section should be sloped down if zeroes behind last point If endslope SlopeArrayBank ArrayBank , num,endpoint-num , ArrayBank[num],0 End If ; Repeat ; Forever ; For num = Offset To endpoint ; If ArrayBank[num] <= 0 ; total = total / divisor ; If total < 0 ; total = 0 ; End If ; ElseIf ArrayBank[num] >= prevvalue ; total = ( total + ArrayBank[num] ) / 2 ; End If ; prevvalue = ArrayBank[num] ; ArrayBank[num] = total ; Next End Function Function SlopeArrayBank( ArrayBank[ArrayBankLimit] , Offset,Size , Value1,Value2 ) Local pos,realpos Local value_dif = Value2 - Value1 For pos = 1 To Size ArrayBank[ pos-1 + Offset ] = Value1 + pos * value_dif / Size Next End Function --v
Mon, 28 Nov 2011, 19:55
Scherererer	For some theory, look up convolution, and specifically using a box filter and a gaussian filter. -=-=- YouTube Twitter Computer Science Series: Logic (pt1) (part 2) (part 3) 2's Complement Mathematics: Basic Differential Calculus