我正在尝试安装tidyverse并加载它。在这样做的同时，面临以下S3问题，方法已声明，但在NAMESPACE 中找不到
library(tidyverse)
undefined exports: abline, arrows, assocplot, axTicks, Axis, axis, axis.Date, axis.POSIXct, barplot, box, boxplot, bxp, cdplot, clip, close.screen, co.intervals, contour, coplot, curve, dotchart, erase.screen, filled.contour, fourfoldplot, frame, grconvertX, grconvertY, grid, hist, identify, image, layout, layout.show, lcm, legend, lines, locator, matlines, matplot, matpoints, mosaicplot, mtext, pairs, panel.smooth, par, persp, pie, plot.design, plot.function, plot.new, plot.window, plot.xy, points, polygon, polypath, rasterImage, rect, rug, screen, segments, smoothScatter, spineplot, split.screen, stars, stem, strheight, stripchart, strwidth, sunflowerplot, symbols, text, title, xinch, xspline, xyinch, yinch, .filled.contour, barplot.default, boxplot.default, boxplot.matrix, contour.default, hist.default, image.default, lines.default, pairs.default, plot.default, points.default, text.default
In addition: Warning message:
S3 methods ‘Axis.default’, ‘Axis.Date’, ‘Axis.POSIXt’, ‘Axis.table’, ‘barplot.default’, ‘barplot.formula’, ‘boxplot.default’, ‘boxplot.formula’, ‘boxplot.matrix’, ‘cdplot.default’, ‘cdplot.formula’, ‘contour.default’, ‘hist.Date’, ‘hist.default’, ‘hist.POSIXt’, ‘identify.default’, ‘image.default’, ‘lines.default’, ‘lines.formula’, ‘lines.histogram’, ‘lines.table’, ‘mosaicplot.default’, ‘mosaicplot.formula’, ‘pairs.default’, ‘pairs.formula’, ‘persp.default’, ‘plot.data.frame’, ‘plot.default’, ‘plot.factor’, ‘plot.formula’, ‘plot.function’, ‘plot.histogram’, ‘plot.raster’, ‘plot.table’, ‘points.default’, ‘points.formula’, ‘points.table’, ‘spineplot.default’, ‘spineplot.formula’, ‘stripchart.default’, ‘stripchart.formula’, ‘sunflowerplot.default’, ‘sunflowerplot.formula’, ‘text.default’, ‘text.formula’ were declared in NAMESPACE but not found
经过长时间的搜索，再次卸载R和RStudio似乎更好。之后问题就解决了。
这似乎不是正确的解决方案，但无论如何都奏效了。