2

If I have a shapely multiline object that contains many lines whose total length each is 50km (when traced from the origin), and I want to interpolate along the multiline every X meters (let's say 100m), returning shapely point objects every 100m, how can I achieve this?

Here is what I have so far, but it only returns one distinct point (when I know it should return several thousand, as tested in ArcMap):

points = []

for x in range(100,50000,100):
    x,y = multiline.interpolate(x).xy
    xy = (x[0],y[0])
    points.append(xy)

trim = list(set(points))

And here is what trim contains:

[(-90.5864707030599, 38.4688716729703)]

If I break the multiline into individual lines, I can get more points (162), but still not the 1000s I should generate:

# breaking out individual lines into shapely line strings
for line in multiline:
    lines_shapes.append(gm.asLineString(line))

points = []

# interpolating points along each line
for line in lines_shapes:
    for x in range(100,50000,100):
        points.append(line.interpolate(100))

point_list = []
for point in points:
    x,y = point.xy
    xy = (x[0],y[0])
    point_list.append(xy)

trim = list(set(point_list))

and trim contains:

[(-90.4766827033434, 38.5972414054466), (-90.5461231698478, 38.5000688058116), (-90.4968889030998, 38.5464768729898), (-90.6189469029766, 38.4718782063951), (-90.513144169767, 38.5129150061034), (-90.5810937033111, 38.5323612724354), (-90.5396967035394, 38.5864442726652), (-90.6868857696619, 38.447798672452), (-90.6213193028429, 38.5146844725911), (-90.509758103553, 38.5536796727591), (-90.476078103521, 38.546296205486), (-90.6427893693333, 38.5555682724382), (-90.6217561026614, 38.5147302723649), (-90.630436369842, 38.5000560723107), (-90.4760629697296, 38.5914768059899), (-90.6849423697939, 38.4566312056467), (-90.6538383698443, 38.4599348058277), (-90.4699029698455, 38.5837950057152), (-90.6694679700701, 38.4474470726055), (-90.6829395031549, 38.4198408724397), (-90.6732927030951, 38.4360894058827), (-90.5866617028747, 38.5332390062557), (-90.6961129028875, 38.4531938061303), (-90.5947731029956, 38.4539120730648), (-90.5142317702794, 38.5249724721824), (-90.5903123694197, 38.5034458725098), (-90.5755567699284, 38.5000690063604), (-90.56752770364, 38.5589170059954), (-90.6271141698824, 38.5430544723665), (-90.6201437702182, 38.4550620064875), (-90.6180047030539, 38.5000570723568), (-90.6589975699812, 38.500065872223), (-90.685946302779, 38.4505508056563), (-90.6840849030951, 38.4547842059075), (-90.6854941029699, 38.4134104059469), (-90.5918703027716, 38.5000662058715), (-90.5471115031927, 38.4808140060424), (-90.463451370184, 38.5525954725834), (-90.6780159694608, 38.4460308724081), (-90.5896267029094, 38.5346980060887), (-90.5807949701111, 38.5325790054973), (-90.7004947695174, 38.4727768728354), (-90.5955769035506, 38.5373834725497), (-90.6569789697031, 38.4542776061077), (-90.6253669031594, 38.521868606032), (-90.6565429028321, 38.4538942062337), (-90.4636589696851, 38.552869806277), (-90.634338969767, 38.546211672811), (-90.4360581033981, 38.5162080059754), (-90.478937169714, 38.604583072231), (-90.6238845029668, 38.5403794056656), (-90.5115069701699, 38.5170084061937), (-90.6607629031848, 38.4788458064697), (-90.6182993029698, 38.4996076730365), (-90.6795531698423, 38.4464060057138), (-90.5715115033526, 38.5319224725247), (-90.6601255698386, 38.4660196727507), (-90.5944027028219, 38.4399328061353), (-90.6658113032484, 38.5630904727274), (-90.657297702926, 38.4486316730944), (-90.6076871697265, 38.5411054058703), (-90.5189131030566, 38.4958198724699), (-90.4633435036991, 38.5571938060298), (-90.4550633700778, 38.5794588057595), (-90.6551231026484, 38.5026692062996), (-90.6304847695558, 38.4814012057819), (-90.6293281694588, 38.5510622058365), (-90.5337045036593, 38.5480590727484), (-90.5636725699325, 38.5031146728847), (-90.5893179035978, 38.5349642063136), (-90.5502847700255, 38.5531414725813), (-90.6577657029242, 38.4673132728702), (-90.6842995029191, 38.45499127301), (-90.596995102941, 38.536759005804), (-90.4590855033927, 38.579707805551), (-90.618116169525, 38.5138608060121), (-90.662823570151, 38.4436198061903), (-90.5324573031614, 38.5290608063917), (-90.4761187699646, 38.5460198060497), (-90.4365065035716, 38.5163978060946), (-90.5993421032549, 38.4517628723399), (-90.6580597695421, 38.4672556730918), (-90.4697125698785, 38.5713498724789), (-90.6246789694582, 38.5225716726252), (-90.5623807028065, 38.539724406037), (-90.5255411029389, 38.5592538722488), (-90.6779729027267, 38.4309624725214), (-90.5757351702413, 38.5712982055281), (-90.4349003036055, 38.5470764060318), (-90.4881969699136, 38.5968882057062), (-90.5654833701608, 38.5641550721791), (-90.6243467697869, 38.5407896062358), (-90.6833993696845, 38.4554192064123), (-90.5125843031225, 38.5353802722622), (-90.4343933036075, 38.5320694055591), (-90.5949243033133, 38.4437996058484), (-90.6531879693487, 38.5465062727268), (-90.4678253704438, 38.5769334060321), (-90.6560765692776, 38.4512860059256), (-90.6705015033411, 38.4387672065226), (-90.4510205703424, 38.5293378056758), (-90.5965189694742, 38.453478006286), (-90.5158851037139, 38.5293438059525), (-90.5153219032826, 38.5000608728918), (-90.571685370183, 38.5322450728324), (-90.5907731028958, 38.5035282063425), (-90.562387970228, 38.5396736725824), (-90.5632127699527, 38.5000698058576), (-90.4351277034801, 38.5467304062636), (-90.6846297033974, 38.4247822729648), (-90.4300920979354, 38.5121736658553), (-90.6077071031996, 38.5414430059705), (-90.700472969951, 38.4725166728872), (-90.6083531698623, 38.5440140058222), (-90.6611483697009, 38.478763472637), (-90.5148001696915, 38.5340326723505), (-90.6261891029441, 38.4987850056043), (-90.6077131034763, 38.5415200724739), (-90.5714903701838, 38.5588274721905), (-90.487086969987, 38.5953794059149), (-90.6309363029674, 38.4813284731115), (-90.4375485030603, 38.5798804061361), (-90.4348689037762, 38.5318386727971), (-90.4636395029601, 38.5528440056267), (-90.5537693695601, 38.5918534726398), (-90.686189369743, 38.45065887269), (-90.5137219032426, 38.5459956061927), (-90.4708333032137, 38.5588582056221), (-90.562663570167, 38.5400910056759), (-90.5898827695735, 38.4573650056716), (-90.6541333699584, 38.4598728056666), (-90.5201981695093, 38.5275174726339), (-90.5279559031418, 38.5197458058049), (-90.4969485029704, 38.5468012728409), (-90.6963449693442, 38.4523242057786), (-90.5869187695849, 38.5329812056987), (-90.7090465028932, 38.4391836726696), (-90.4722723695735, 38.5676876055788), (-90.6076811029, 38.541104472374), (-90.6281757035453, 38.4421816724275), (-90.5341799698291, 38.5482110060135), (-90.5948001033415, 38.494925272764), (-90.5864707030599, 38.4688716729703), (-90.5419337032772, 38.5685326058754), (-90.7019565698392, 38.4481112057488), (-90.6253121695204, 38.521868606032), (-90.5138205031131, 38.5456764727715), (-90.5529913031055, 38.455285806376), (-90.5293321032933, 38.5986526054135), (-90.6309013697018, 38.5463032723585), (-90.4975365696563, 38.6037882720911), (-90.6184813032689, 38.4720362730366), (-90.6781275699308, 38.4462692727899), (-90.5651579702635, 38.4796824727488), (-90.6532305027848, 38.5024180058671), (-90.6545907030978, 38.5581974062657), (-90.5950401027179, 38.4950944055632), (-90.6468105700511, 38.5573522728695), (-90.6698367029009, 38.4476676727061), (-90.4501431701705, 38.5848148728883), (-90.577996903134, 38.503304272455), (-90.6713375697724, 38.545723072942)]

Maybe the problem is in the argument I am passing to interpolate? How do I know what units it expects/is assuming the distance is in?

0

I've a similar need. There's a helpful Geospatiality blog post that looks as though it provides a suitable solution.

  • I had solved this, but damn if I remember how - it was almost 3 years ago now..... – traggatmot Jan 15 at 15:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.