title: Cluster A Matrix of Distances
body: <p>I have a dataframe of distances between stores, and I would like to produce an object, (list, dataframe, matrix) which shows only those stores which are less than five miles from each other.</p>
  
  <pre><code>foo &lt;- structure(list(`Store 10` = c(97.182714060764, 0, 104.545505520858,120.848327689344, 21.4956940498461, 71.2102784197574, 9.17403190899889,232.086794775442, 43.8173227163331, 116.039010056627),  
                        `Store 100` = c(74.2475604028815,23.3746751242071, 81.1712781831004, 144.120931315268, 23.4110542291118,94.4577722550024, 31.5739132041779, 209.492371721166, 66.6219804313243,92.7938789352653),  
                        `Store 101` = c(19.0839143178718, 104.545505520858,0, 225.069522157464, 96.7190014732743, 175.476702723702, 112.459326421784,133.381899232519, 147.25396306609, 15.0815963235646),  
                        `Store 11` = c(71.2541974994427,26.3632751561921, 78.1889204614728, 147.127665374137, 24.9756132579165,97.4001827503847, 34.5816273110414, 206.517729238781, 69.5004052925104,89.8749246302702),  
                        `Store 113` = c(47.0881131319699, 50.6021433483968,54.2297393980493, 171.433305152348, 43.4877656302823, 121.27129019099,58.9080280322994, 182.467788036299, 93.0266775510096, 66.6478219738416),  
                        `Store 114` = c(19.3082927142542, 103.863224882231, 0.902204635805178,224.353450878124, 96.1678237911265, 174.82195092457, 111.752223369642,134.253268603651, 146.61996769538, 15.2076513974641),  
                        `Store 115` = c(46.1022549798483,139.935108222076, 35.5378432580255, 260.571940423921, 131.050291660978,210.672320747685, 147.943684720518, 100.604144112037, 182.304038294648,28.0600979672013),  
                        `Store 116` = c(115.977910525396, 22.2743738090946,124.975555327727, 102.631253530033, 31.2636483056516, 50.7113682121305,18.9828219549928, 249.513008836821, 22.2791136562013, 137.099156498485),  
                        `Store 121` = c(46.8649813497236, 138.05949112722, 33.6309330793517,258.355746842495, 130.216167069666, 209.073236612232, 145.841428480987,106.026865528358, 180.880981791045, 23.5225484914477),  
                        `Store 122` = c(105.765734973956,9.17403190899889, 112.459326421784, 112.635113034315, 29.7123946609901,64.2530835558693, 0, 240.864256496468, 38.1560918075898, 123.514728759801),  
                        `Store 123` = c(40.3098694204528, 133.529478517196, 29.0974945685631,254.144085030474, 124.817814759525, 204.30698545979, 141.519160181814,106.485062095671, 175.963360773997, 22.2402993792639),  
                        `Store 124` = c(15.4826131889244,109.72589102537, 10.6559300294596, 230.562026431413, 100.032138241845,180.057734012961, 117.996983784268, 125.132767519462, 151.574939557027,20.7774566354144),  
                        `Store 126` = c(80.4918388261617, 20.1645024607666,90.2108352624732, 137.940344444399, 8.19173113521019, 86.1818977331406,29.2603494697063, 214.189063275208, 57.5661773515707, 102.98401126524),  
                        `Store 127` = c(50.5707899850002, 47.9998858006402, 56.5458773807153,168.658302706349, 42.7349808287988, 119.013256474241, 56.0276915534435,185.942422263827, 90.979153440465, 68.3777607965505),  
                        `Store 128` = c(62.3985613534241,156.467009507205, 51.9662381582155, 277.034745305523, 147.628704344456,227.253259800475, 164.424437950093, 87.7741708055936, 198.897034347146,42.853904907684),  
                        `Store 129` = c(44.4280683852888, 53.1076715622684,54.7594044775595, 173.567416520927, 42.09009359735, 122.269218220088,61.9327484138037, 178.979190967292, 93.684829649538, 68.3502152424742),  
                        `Store 130` = c(29.6627438540889, 121.877375024469, 17.5379868044159,242.512526852249, 113.273456996737, 192.656341703268, 129.882659850672,116.636306650557, 164.32413853956, 14.5836446177209),  
                        `Store 131` = c(42.5311323410154,137.779593313915, 34.1439587366749, 258.570280063638, 128.147397896773,208.229343539775, 145.950719450894, 99.9856701001915, 179.755056696375,29.1673894333183),  
                        `Store 132` = c(155.558743492221, 60.771528260534,164.669885634013, 65.0176561457482, 69.959758550586, 11.3767524543355,54.3203426272865, 288.338559299794, 17.5083349593977, 176.63102062546),  
                        `Store 133` = c(50.8336976425147, 144.449880156622, 39.9580651232559,265.02740840713, 135.720410143754, 215.24691301159, 152.412539463999,97.5389327984704, 186.904554971329, 31.5227184037659),  
                        `Store 135` = c(63.3313266209041,157.175042409662, 52.6467805600477, 277.701522855422, 148.458750384611,228.000622471795, 165.103767022962, 87.8385721010536, 199.664633999748,43.2605181145178),  
                        `Store 136` = c(61.8710249192055, 154.122020212753,49.6640907492411, 274.390910797956, 146.117217151602, 225.128094850195,161.895945075365, 93.5747028772301, 196.917181955845, 39.0757329765446),  
                        `Store 137` = c(103.313457349294, 17.3461827402428, 113.229054795412,116.112422661667, 17.7120593551046, 63.5719949243665, 20.4028086903726,236.187273346596, 34.8714799448828, 125.874876880014),  
                        `Store 139` = c(71.8160418260827,164.107026385352, 59.7067114286829, 284.279664826551, 156.194082461646,235.146144930092, 171.835462193164, 87.4721917453367, 206.95916222963,48.7051425613191),  
                        `Store 14` = c(69.9026102953175, 27.6682921924945,76.8975949005597, 148.453900730172, 25.5703428825346, 98.6613132535166,35.9228707805444, 205.163394506493, 70.7179161568892, 88.638643540865),  
                        `Store 141` = c(160.447782224841, 65.2717814365252, 169.388864785603,59.9444789236008, 74.9450028320972, 6.30907948029094, 58.5421265869609,293.360566048771, 22.4271238094327, 181.242078615482),  
                        `Store 143` = c(94.4967558026401,16.3844028106868, 104.624495877666, 124.844515480636, 8.99230765291032,72.4097871621613, 22.9930146589562, 227.386414291682, 43.7102809488183,117.434599522384),  
                        `Store 144` = c(30.6406755152047, 68.6112712822058,44.4695702684719, 188.558533806214, 55.6147674023494, 136.671637702601,77.5500247906599, 163.646263814946, 107.983907652985, 59.1750702503532),  
                        `Store 145` = c(116.634237264487, 23.6359859109202, 125.843931060261,102.259873126813, 31.5514229455087, 50.039873981195, 20.6409773826946,249.951334197986, 21.4569059128841, 138.065135950694),  
                        `Store 146` = c(49.0568193512663,54.311278216063, 51.5682497967442, 173.872187121451, 51.8366521189428,125.496883714123, 61.5757017052046, 183.451756458655, 97.9724963791237,61.9504010810814),  
                        `Store 147` = c(0, 97.182714060764, 19.0839143178718,217.908876952855, 85.9859121607294, 166.67126390107, 105.765734973956,135.391012347645, 138.050987597536, 33.6823000691004),  
                        `Store 148` = c(48.2299284841927,53.7142932078625, 51.5598052976402, 173.640099206422, 50.4421662885367,124.924567331259, 61.1836277867489, 182.958179140963, 97.2494257434835,62.3601665165924),  
                        `Store 149` = c(49.9477288326237, 52.1431794480886,53.2674613906208, 171.968693905148, 49.3117412727633, 123.350162356965,59.5479342705133, 184.700460684605, 95.7315747878528, 63.9749611826139),  
                        `Store 15` = c(82.5768888008737, 15.4683626243912, 89.2381403030532,135.920084787888, 21.9407747294326, 86.6764572064895, 23.3053648689151,217.826144766742, 59.181641916233, 100.588426031137),  
                        `Store 150` = c(111.470597382221,14.5119998977806, 118.221849873196, 106.872183476945, 33.6852827380805,58.7080741940326, 5.76337578744118, 246.512942912896, 33.2309002398316,129.247939288897),  
                        `Store 151` = c(85.5164627172282, 21.0650021470382,89.719717608509, 136.048733561359, 33.5514294236898, 89.3823249007233,25.3616871032807, 220.808335030956, 63.4667089762883, 99.7490148934809),  
                        `Store 152` = c(65.7333609050899, 159.708693014139, 55.1846211658909,280.242160041282, 150.943739032955, 230.523732896797, 167.642654764196,85.7426951335072, 202.180426706117, 45.7642994377334),  
                        `Store 153` = c(59.3579242287549,149.610092014953, 45.6143412842972, 269.559143541198, 142.330605461009,220.738288755992, 157.22437780625, 100.319798887199, 192.668333201516,33.8384127325631),  
                        `Store 154` = c(14.6177046456285, 105.321597967839,5.80210070409739, 226.091584853407, 96.3550552882973, 175.921089463583,113.468746014001, 130.422441769589, 147.528879548255, 19.1326831571266),  
                        `Store 155` = c(98.0521250589665, 14.9615837614282, 107.891590694071,121.044929404276, 12.842867538134, 68.7318498691966, 20.3433651716831,231.147101768248, 40.0455203560419, 120.545097753848),  
                        `Store 158` = c(127.28518481773,30.2013867691535, 134.667667307237, 90.6598544948954, 45.3406347212269,42.0113596970615, 22.4099907573838, 261.906676938723, 18.6101002948444,145.890690285015),  
                        `Store 159` = c(67.6749186168928, 158.91047585088,54.7277366056853, 278.919460342222, 151.389358118033, 230.013706144037,166.557956365005, 93.0065500154447, 201.902095297973, 43.2119219139315),  
                        `Store 160` = c(110.120232119226, 20.8254695717587, 119.897083434758,109.392676953945, 24.4967523202215, 56.7555673594198, 20.9182993439403,242.976497116235, 28.0547337715745, 132.430245082595),  
                        `Store 161` = c(138.113572784299,45.0931604978753, 147.748517674391, 82.7382855546652, 52.2879796050827,29.2315784133779, 40.03378203141, 270.539048139633, 3.72405642504832,160.050898616871),  
                        `Store 162` = c(39.5318874970135, 58.2426177248329,46.7674666037364, 179.080302234251, 50.3530377561357, 128.818374320699,66.5595692995086, 174.922803603218, 100.509780214086, 59.5159959177498),  
                        `Store 163` = c(113.898151873892, 21.8503465903741, 123.256785979153,105.115182928792, 28.6934110323499, 52.7968063588392, 19.914038455521,247.118360982377, 24.1551906075442, 135.568043716944),  
                        `Store 164` = c(167.296800589537,72.5538864322338, 176.493531722362, 54.7266951318064, 81.5741222821151,4.06885914637227, 65.9373166073689, 299.806169163016, 29.2845708803529,188.451665473381),  
                        `Store 165` = c(100.861353629287, 18.3110449793727,104.973470818329, 121.439421883486, 38.4023517429513, 76.6187217512178,16.1847822790123, 236.179406006191, 52.7160110816438, 114.687045845975),  
                        `Store 166` = c(84.2309696787776, 26.0860582793184, 87.4029960514953,139.227141903611, 38.1811729600301, 93.434701169323, 29.8197291133567,219.249743646815, 67.9751869268833, 96.8901622223067),  
                        `Store 167` = c(42.6659873965625,54.71184818961, 52.7896560771485, 175.274216597181, 44.0219182175731,124.078866519639, 63.4825184989626, 177.390013796269, 95.5146942756369,66.3595384524349),  
                        `Store 168` = c(27.9588076795691, 69.7279066991086,40.3368579277696, 190.19369821024, 58.0608388931474, 138.737127622791,78.5070370487016, 162.366317609087, 110.102409513181, 54.8303582440215),  
                        `Store 169` = c(69.3159383038625, 27.9806959835842, 76.7505745526877,148.828132946066, 24.427921667524, 98.7337533354309, 36.4499470061253,204.475568144805, 70.6516437376385, 88.7015577637252),  
                        `Store 170` = c(21.5182328406625,81.0766121041097, 23.5040887504589, 201.7123753104, 73.5685355110635,151.972652223415, 89.0780912882125, 154.463389583329, 123.763124828067,36.3513987268101),  
                        `Store 171` = c(44.113714476827, 141.170390840861,40.7099024063727, 261.969465961018, 129.923502112083, 210.767960750873,149.643621219947, 92.8741873982887, 182.130236923797, 39.1531976152106),  
                        `Store 172` = c(19.7849976772945, 81.7327152729014, 23.0557408490977,202.456573054471, 73.7396811249913, 152.509772689368, 89.8263447104721,153.235986420409, 124.231532446728, 36.3930683039177),  
                        `Store 173` = c(18.0896049763375,81.7180794297641, 23.7146422241885, 202.531152805935, 73.0324966127671,152.282200543921, 89.9452137081293, 152.432264250142, 123.912487479355,37.6141760528144),  
                        `Store 174` = c(36.8897611134, 134.055684768267,35.3860918685918, 254.798580870764, 122.521779120797, 203.446863653305,142.593386316348, 99.2011320960102, 174.79194894808, 36.3508939538918),  
                        `Store 175` = c(19.4055088776882, 116.574724359947, 23.3648681171702,237.25992572555, 104.929272535089, 185.845524690095, 125.170594980623,116.077864702495, 157.189185893232, 31.3550210113149),  
                        `Store 176` = c(122.111235017339,31.0308415808054, 131.964915536305, 98.2014379071899, 36.2667125370514,45.0713484742342, 28.1298214696256, 254.596980227275, 16.5153465948402,144.457436271883),  
                        `Store 177` = c(174.312564632948, 79.1922090280055,183.340294466275, 47.8073182354175, 88.6625262979693, 8.09591435748952,72.3206532781363, 306.943427288542, 36.2623491601668, 195.185377885561),  
                        `Store 178` = c(124.61219657824, 29.2189874552703, 133.185169837572,93.7227786978209, 40.2544721298839, 42.2933454932431, 23.5771031889714,258.394559593159, 14.6785036558556, 145.039824993218),  
                        `Store 179` = c(24.061240178573,73.6283030875174, 32.5698473716518, 194.474670260206, 64.2598509447223,143.868493927243, 82.0380354121153, 159.429322108816, 115.415891099251,46.4566844521991),  
                        `Store 180` = c(44.9701847904077, 53.5741556808663,56.5028532974761, 173.52782156235, 41.0332449596439, 121.809685121786,62.5506909595459, 178.713172704501, 93.1490182636026, 70.441327010977),  
                        `Store 181` = c(111.967567861059, 15.3395480941109, 118.456513677175,106.613028699201, 35.0444361312221, 58.9787865880595, 6.25161265482528,247.099102496894, 34.0064929129624, 129.338722956737),  
                        `Store 182` = c(60.3456838723146,157.165746321455, 54.8712719155892, 278.007492402975, 146.264575168245,227.01038283941, 165.54630457556, 78.9129302783064, 198.39647719976,49.9351821713357),  
                        `Store 183` = c(13.4908806737511, 106.989824235947,9.21244068502985, 227.822410878512, 97.4026538853887, 177.355731406986,115.251274704921, 127.837556171709, 148.88531616473, 21.2420515177377),  
                        `Store 184` = c(111.033225406542, 19.2764979102658, 120.345826022698,107.824773824757, 26.0137323203271, 55.6456779424236, 18.2181155011756,244.358639647822, 27.0332546214697, 132.655884995622),  
                        `Store 185` = c(121.308917445053,26.4252993976045, 130.039503153969, 97.124054050421, 36.8181137758406,45.4805165537354, 21.5036756085157, 255.000788916903, 17.4208150256445,141.995038580212),  
                        `Store 186` = c(84.839269969394, 21.5242708074613,95.4923419326264, 134.770659233404, 1.2764208987712, 82.2799328459307,29.9352010285124, 217.469820029272, 53.5799208540953, 108.608440764191),  
                        `Store 187` = c(70.762830554532, 26.7493232717837, 77.8264470408527,147.549192114017, 24.7936684973839, 97.7236536067102, 35.0395450196894,206.002392522627, 69.7738084636148, 89.5813570895854),  
                        `Store 188` = c(73.4914682940968,166.142669957365, 61.6880533608055, 286.372456277449, 158.08397622017,237.153772934312, 173.900880020558, 85.3267010710687, 208.939606223087,50.8679871357349),  
                        `Store 189` = c(30.6335264648226, 123.256891318455,18.9764035968927, 243.911262897971, 114.550626876199, 194.008128743653,131.27901530561, 115.178276808933, 165.660950927686, 15.68699143228),  
                        `Store 19` = c(23.3642987684607, 78.6445238327238, 25.9240409323312,199.275549425542, 71.2620727787222, 149.554161877786, 86.6413245639711,156.793548788537, 121.358188826921, 38.6120813160024),  
                        `Store 190` = c(24.8953566793903,117.245571156207, 13.3340327832417, 237.944432716928, 108.445877146219,187.947611720127, 125.309321393313, 120.152382559651, 159.583855382627,14.6647069749799),  
                        `Store 191` = c(155.549777905836, 59.2045930103401,163.721983356225, 62.8685411134829, 70.9404199229136, 12.9854946588728,51.8374805070557, 289.315677754038, 19.3149032304898, 175.194340788389),  
                        `Store 192` = c(91.4872714349676, 20.7420409870123, 102.303830906892,128.795763082887, 5.5849073536186, 75.9919896582289, 27.8657918252687,223.671926751966, 47.3273985563995, 115.43062460952),  
                        `Store 193` = c(141.719380784307,44.7308064777817, 149.21549633528, 76.1901979874281, 58.6478661940372,28.2986343042698, 36.8888272114097, 276.148618719698, 14.5982071991189,160.401940554441),  
                        `Store 194` = c(48.514585801489, 53.9192393293824,51.5507325193362, 173.721059423255, 50.9351331055158, 125.126181046054,61.3161015133771, 183.130645867563, 97.5039715964655, 62.2037250260579),  
                        `Store 195` = c(164.817466984655, 68.4273774676872, 172.961113991137,53.7638946100393, 80.0923517591417, 6.92931132757607, 60.9386983862209,298.518399895709, 27.9982779422079, 184.375889358264),  
                        `Store 196` = c(57.8791543420262,39.8731109468306, 64.7367364412644, 160.662187066822, 34.7483617119882,110.75845281183, 48.0982056977083, 193.235019566556, 82.6699385366847,76.7036279641455),  
                        `Store 197` = c(82.3340701244326, 24.430876802672,93.3620542941436, 137.6952453344, 3.89925888328242, 85.0666101440906,32.9745290918747, 214.623799032827, 56.3779006738775, 106.651209674791), 
                        `Store 198` = c(61.7331430932174, 41.6180605526713, 74.0615309657223,158.728662838499, 24.966286291908, 106.183761957946, 50.7830769428203,193.514274891317, 77.4948060082806, 88.0144312091132),  
                        `Store 199` = c(166.67126390107,71.2102784197574, 175.476702723702, 53.7367961521279, 81.2330368742957,0, 64.2530835558693, 299.662194368447, 28.7008518753862, 187.234252564455), 
                        `Store 2` = c(71.4306146651704, 26.1188858912486, 78.4436621201813,146.904747423482, 24.5812050041696, 97.1253757139686, 34.380881492236,206.676269143349, 69.2034635209456, 90.1621318945159), 
                        `Store 200` = c(138.050987597536,43.8173227163331, 147.25396306609, 81.6884783765538, 52.5372484426156,28.7008518753862, 38.1560918075898, 270.994160457313, 0, 159.343872952503), 
                        `Store 201` = c(167.299937831438, 71.0085926507406, 175.530197092849,51.5242300593162, 82.435859482383, 5.77433520197501, 63.5665101049999,300.893950302255, 30.1648913107489, 186.980778244732), 
                        `Store 202` = c(75.8142152145889,168.978523628256, 64.4657604762506, 289.293568083503, 160.696477104858,239.941616470381, 176.782830387055, 82.1915792024463, 211.68656304804,53.9228716088697), 
                        `Store 203` = c(84.4342251533454, 22.3413358736533,95.2178146219974, 135.345773392241, 1.55941180174149, 82.7893845620659,30.7454280782317, 216.929767592851, 54.0927852258926, 108.390557720654), 
                        `Store 204` = c(22.1143205044024, 114.156359921168, 10.5669818888741,234.871499237087, 105.333331209187, 184.839958871956, 122.236961768806,122.814937270634, 156.471470077292, 14.94366299403), 
                        `Store 205` = c(122.1867570939,35.6035124272749, 133.012362035619, 100.894788979297, 36.3496927542645,47.205327605463, 34.2399762735442, 253.324976689857, 20.2203608687206,145.950349598117), 
                        `Store 206` = c(70.1191986671587, 167.111567817173,65.0342316301412, 287.93466221017, 155.89462732924, 236.774146245167,175.536143580105, 68.9290424392404, 208.133198902687, 59.7418624930726), 
                        `Store 207` = c(88.5687945825953, 20.1658244721324, 99.2013792438283,131.220345824945, 2.60896587403033, 78.6245234271278, 28.0000435453275,221.084868654116, 49.929251874617, 112.276065981859), 
                        `Store 208` = c(85.9859121607294,21.4956940498461, 96.7190014732743, 133.808566486628, 0, 81.2330368742957,29.7123946609901, 218.480538056125, 52.5372484426156, 109.857440510197), 
                        `Store 209` = c(121.663640082533, 28.9006139146935, 131.070615054781,97.7229173210449, 36.1960660065879, 45.0888689432883, 25.2658849461922,254.676555811973, 16.3993052713823, 143.353549283483), 
                        `Store 21` = c(36.0480404047006,61.9873611681417, 42.9777748186856, 182.813207902126, 54.0670953074946,132.604605615094, 70.2611511460531, 171.413791566702, 104.300827164642,55.7904226028449), 
                        `Store 210` = c(141.172490571705, 47.590467181754,150.654610539172, 79.4675863369946, 55.4174448807273, 25.9907325466536,42.1310486296248, 273.73242009186, 4.06432884804506, 162.867201320882), 
                        `Store 211` = c(195.549857773211, 99.0907594141363, 203.636015465996,24.5734528986502, 110.560998346534, 29.5859891297109, 91.3903210186264,329.041527102902, 58.0778758968437, 214.904399633133),  
                        `Store 212` = c(19.8758322224963,79.5858453380513, 35.6533601753144, 199.72077031221, 66.8023296885385,147.875689075413, 88.4567582084607, 152.550832647225, 119.187833806082,50.6967832261861),  
                        `Store 213` = c(208.422391774923, 111.355422226041,215.585707126769, 9.49312702759228, 124.417581698746, 44.7662840289739,103.146190321542, 342.670576447407, 72.4193928009537, 226.294313616523),  
                        `Store 214` = c(57.4796622794928, 154.555666730667, 53.3509827699372,275.352996387969, 143.19987077126, 224.106641472437, 163.024900930719,80.036615273364, 195.458347761762, 49.6929091134769)), 
                  .Names = c("Store 10","Store 100", "Store 101", "Store 11", "Store 113", "Store 114","Store 115", "Store 116", "Store 121", "Store 122", "Store 123","Store 124", "Store 126", "Store 127", "Store 128", "Store 129","Store 130", "Store 131", "Store 132", "Store 133", "Store 135","Store 136", "Store 137", "Store 139", "Store 14", "Store 141","Store 143", "Store 144", "Store 145", "Store 146", "Store 147","Store 148", "Store 149", "Store 15", "Store 150", "Store 151","Store 152", "Store 153", "Store 154", "Store 155", "Store 158","Store 159", "Store 160", "Store 161", "Store 162", "Store 163","Store 164", "Store 165", "Store 166", "Store 167", "Store 168","Store 169", "Store 170", "Store 171", "Store 172", "Store 173","Store 174", "Store 175", "Store 176", "Store 177", "Store 178","Store 179", "Store 180", "Store 181", "Store 182", "Store 183","Store 184", "Store 185", "Store 186", "Store 187", "Store 188","Store 189", "Store 19", "Store 190", "Store 191", "Store 192","Store 193", "Store 194", "Store 195", "Store 196", "Store 197","Store 198", "Store 199", "Store 2", "Store 200", "Store 201","Store 202", "Store 203", "Store 204", "Store 205", "Store 206","Store 207", "Store 208", "Store 209", "Store 21", "Store 210","Store 211", "Store 212", "Store 213", "Store 214"), 
                  row.names = c("Store 147","Store 10", "Store 101", "Store 434", "Store 208", "Store 199","Store 122", "Store 593", "Store 200", "Store 502"), 
                  class = "data.frame") 
  ==X==============================================================X==
  </code></pre>