下面是我的代码和附加的绘图结果：

g <-ggplot(NDVI2, aes(LAI2, NDVI, colour = Legend)) + 
    theme_bw (base_family = "Times") + 
    scale_colour_manual (values = c("purple", "green", "blue", "yellow",  "magenta","orange", "cyan", "red", "black")) + 
    geom_point (size = 3) +
    geom_smooth (aes(group = 1, colour = "Trendline"), method = "loess", size = 1, linetype = 5, se = FALSE) +
    geom_smooth (aes(group = 1, colour = "Regression (log)"),linetype = 1, size=1.2,method = "lm", formula = y~ log(x), se = FALSE) + 
    labs (title = "Correlation of LAI and NDVI")+ 
    theme (legend.title = element_text (size = 15))

这导致了这个图：

正如你所看到的，所有的传奇图标看起来都一样。我想要的是，点显示为点，两条线（“回归”和“趋势线”）显示为线。
我试着用

guides (colour = guide_legend (override.aes = list(size = 1.5)))

但这又给了我所有的图标以同样的方式，我不知道如何区分它们
我是R的新手，这是我的第一个“复杂”的情节。试图找出最与在线帮助和谷歌，但找不到解决这个问题的办法。感谢大家的时间和帮助！
下面是我的dput数据：

NDVI2 <- read.table(header = TRUE, text = "
          MeanRED    MeanNIR          NDVI              LAI2 Legend
'LAI 1-1' 3.240264   46.8226195806452 0.870552242769623 1.1  LAI 1
'LAI 1-2' 6.97950484 48.4417953548387 0.748129155560663 1.2  LAI 1
'LAI 1-3' 3.75052276 47.8913064516129 0.854748647859414 1.3  LAI 1
'LAI 1-4' 4.62617908 43.9416386774194 0.809496111062421 1.4  LAI 1
'LAI 2-1' 4.07743944 44.7524788709677 0.832994214160536 2.1  LAI 2
'LAI 2-2' 4.88961572 52.2142607741935 0.828746627367857 2.2  LAI 2
'LAI 2-3' 3.15865532 48.6422146774194 0.878046244390978 2.3  LAI 2
'LAI 2-4' 2.28368236 44.6617992580645 0.902709173224405 2.4  LAI 2
'LAI 3-1' 3.40793788 57.7213822580645 0.888500710549276 3.1  LAI 3
'LAI 3-2' 4.28833416 58.5066447096774 0.863417928083076 3.2  LAI 3
'LAI 3-3' 4.52529496 56.6924350967742 0.852157374806182 3.3  LAI 3
'LAI 3-4' 2.45698208 57.4100250967742 0.917918660181389 3.4  LAI 3
'LAI 4-1' 3.84003364 58.0419292903226 0.875891666709934 4.1  LAI 4
'LAI 4-2' 4.31006672 58.7054423225806 0.863206160341016 4.2  LAI 4
'LAI 4-3' 3.29672264 58.5283540645161 0.893353221193523 4.3  LAI 4
'LAI 4-4' 4.21926652 54.7658463548387 0.856937918252258 4.4  LAI 4
'LAI 5-1' 4.64357012 58.8950077096774 0.853834622095331 5.1  LAI 5
'LAI 5-2' 3.94445908 58.2421209354839 0.873141147848366 5.2  LAI 5
'LAI 5-3' 3.95942484 57.8538210645161 0.871890732089488 5.3  LAI 5
'LAI 5-4' 1.22673756 50.209727516129  0.952300860559358 5.4  LAI 5
'LAI 6-1' 4.70933136 59.5780209354839 0.853491201866442 6.1  LAI 6
'LAI 6-2' 5.33718396 60.1662100645161 0.837040994913869 6.2  LAI 6
'LAI 6-3' 5.71857348 62.1929408387097 0.831587513918106 6.3  LAI 6
'LAI 6-4' 5.7014266  60.3309026451613 0.827314084928549 6.4  LAI 6
'LAI 7-1' 3.85938572 57.859932516129  0.874937512911774 7.1  LAI 7
'LAI 7-2' 6.07816804 63.5678422258065 0.825455384542418 7.2  LAI 7
'LAI 7-3' 2.93602476 55.2536370967742 0.899087753174211 7.3  LAI 7
'LAI 7-4' 5.00289296 60.1808743548387 0.846498808949291 7.4  LAI 7
")