In her new memoir, Calhoun resurfaces material that her father, the art critic Peter Schjeldahl, gathered years ago for a possible biography of the poet Frank O’Hara, who died in 1966, at 40. “Also a Poet” began as Calhoun’s attempt to finish what her father couldn’t, but it turned into a story about both the impossibility of reconstructing another person’s life and the importance of trying — and an investigation of the strained, complicated relationship between a creative father and daughter.