Accessing polyline vector data in leaflet, shinydashboard

[dennis...@gmail.com]

Running leaflet within shinydashboard, I would like to display a shapefile representation of a road map dataset on top of a raster map from OSM.  This is to verify the closeness of fit.  But it is also to prepare to access individual polylines to visually traverse them.  Not a continuous traversal, but simulating motion of, say, 100 meters along the road at a time.

I have used readOGR() from the rgdal package, and readShapeLines() from the maptools package, to read a polyline structure from a shape file.  I see within the data structure what appears to be UTM coordinates.  How are these accessed? I am new to shapefile formats, and how they are placed into R structures.  I can get to a data frame with as.data.fram(), but that only captures the attribute data, not the location data.

Any advice how to proceed?  I can plot the shapefile object in my plot window.  AddPolyLines does not plot anything for me.  On other forums and tutorials, I do see some about how to display this data, or trim it, but I haven't seen anything about accessing the location data.  On the various geo packages, I don't see anything about traversal, identifying junctions, etc.

I have copied below the output of head() for the shapefile object.  I trimmed off some of the repetitive coordinates.  

R 3.2.1

RStudio 0.99.476

leaflet 1.0.0.9999

shinydashboard 0.50.

MacOS 10.8.5

Thanks for any suggestions.

An object of class "SpatialLinesDataFrame"

Slot "data":

    PID MASTER_ID PREFIX            NAME SUFFIX TYPE CLASS ROW_WIDTH

0 40101      1625   <NA> Mission Springs   <NA>   Ct    RE        52

1 18530      1626   <NA>          Berger   <NA>   Dr    RE        77

2 71869      1627   <NA>      Maple Lake   <NA>   Ct    RE        44

3 71870      1628   <NA>           Oneco   <NA>   Ct    RE        46

4 71871      1629   <NA>          Myrick   <NA>   Ct    RE        46

5 71872      1630   <NA>            Loma   <NA>   Ct    RE        51

  FOC_WIDTH     ADD_TYPE FRADD_L FRADD_R TOADD_L TOADD_R MUNI_L MUNI_R ZIP_L

0        38   CONTIGUOUS    1501    1500    1599    1600     SJ     SJ 95131

1        57 STD EVEN ODD    1401    1400    1599    1598     SJ     SJ 95112

2        24 STD EVEN ODD    1700    1701    1798    1799     SJ     SJ 95131

3        26 STD EVEN ODD    1500    1501    1598    1599     SJ     SJ 95131

4        26   CONTIGUOUS    1500      NA    1598      NA     SJ     SJ 95131

5        31         <NA>      NA      NA      NA      NA     SJ     SJ 95131

  ZIP_R PRIVATE ONE_WAY WIDTH HEIGHT WEIGHT SPD_LIM FCODE

0 95131       N       B    NA     NA     NA      25    RE

1 95112       N       B    NA     NA     NA      25    RE

2 95131       Y       B    NA     NA     NA      25    RE

3 95131       Y       B    NA     NA     NA      25    RE

4 95131       Y       B    NA     NA     NA      25    RE

5 95131       Y       B    NA     NA     NA      25    RE

                                NAME_FROM

0 Mission Springs Cl & Mission Springs Ct

1                   Berger Dr & E Gish Rd

2                           Maple Lake Ct

3                  Clampett Wy & Oneco Ct

4                 Clampett Wy & Myrick Ct

5                   Fountain Cl & Loma Ct

                                           NAME_TO

0                               Mission Springs Ct

1 Berger Dr / Golden Wheel MHP Access & Oakland Rd

2                         Bahre Ln & Maple Lake Ct

3                                         Oneco Ct

4                                        Myrick Ct

5                                          Loma Ct

Slot "lines":

[[1]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

         [,1]    [,2]

 [1,] 6158329 1965641

 [2,] 6158320 1965654

 [3,] 6158311 1965666

 [4,] 6158302 1965679

 [5,] 6158293 1965691

 [6,] 6158284 1965704

 [7,] 6158275 1965716

 [8,] 6158263 1965732

 [9,] 6158260 1965736

[10,] 6158258 1965739

[11,] 6158256 1965743

[12,] 6158253 1965746

[13,] 6158250 1965749

[14,] 6158248 1965752

[15,] 6158225 1965784

Slot "ID":

[1] "0"

[[2]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

         [,1]    [,2]

 [1,] 6155696 1960109

 [2,] 6155692 1960113

 [3,] 6155665 1960144

 [4,] 6155663 1960145

 [5,] 6155662 1960147

 [6,] 6155660 1960149

 [7,] 6155659 1960151

 [8,] 6155658 1960152

 [9,] 6155656 1960154

[10,] 6155651 1960164

[11,] 6155646 1960173

[12,] 6155642 1960183

[13,] 6155639 1960194

[14,] 6155637 1960204

[15,] 6155636 1960215

Slot "ID":

[1] "1"

[[3]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

        [,1]    [,2]

[1,] 6156863 1965851

[2,] 6156793 1965965

[3,] 6156786 1965977

Slot "ID":

[1] "2"

[[4]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

        [,1]    [,2]

[1,] 6161802 1968132

[2,] 6161781 1968115

[3,] 6161685 1968039

Slot "ID":

[1] "3"

[[5]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

        [,1]    [,2]

[1,] 6161718 1968239

[2,] 6161695 1968221

[3,] 6161600 1968146

Slot "ID":

[1] "4"

[[6]]

An object of class "Lines"

Slot "Lines":

[[1]]

An object of class "Line"

Slot "coords":

        [,1]    [,2]

[1,] 6153531 1969936

[2,] 6153563 1969942

[3,] 6153584 1969947

[4,] 6153606 1969951

[5,] 6153628 1969956

[6,] 6153650 1969960

[7,] 6153672 1969965

[8,] 6153694 1969969

Slot "ID":

[1] "5"

Slot "bbox":

      min     max

x 6153531 6161802

y 1960109 1969969

Slot "proj4string":

CRS arguments: NA 

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